S4 OPEN: BACNET-N2 ROUTER

This page was eliminated from when we transitioned from our original web site as the power of Internet search engines has eliminated the need for this page. Please use your favorite search engine to look for the terms you need information about.

The S4 Group does not offer this service. However, we do know of multiple companies who:
- Repair automation equipment that is no longer being manufactured or supported by the OEM.
- Offer refurbished or used equipment.

Here is a list of those we are aware of.

Advanced Electronic Services
101 Technology Lane
Mt. Airy, NC - 27030
Phone: 866-386-1001
Email: aes@aesintl.com
Web: https://www.aesintl.com/
Our Core Services include Industrial Electronic, Hydraulic, Mechanical, and Photo Printer Repair.

ASSET Technologies, LLC.
3600 Chamberlain Lane
Suite 122
Louisville, KY 40241
Office: 502-425-8702
Email: sales@a-techs.net
Web: http://www.a-techs.net

Building Automation Repair Service , LLC
5203 Windy Willow Dr
Louisville, KY 40241
Chad Hardesty
Phone #:502-641-9267
Email: Chad.Hardesty@bars-llc.com
Web: https://www.barsglobal.com

Global Electronic Services
5325 Palmero Court
Buford, GA 30518
USA
Account Manager
BJ Mackler
Phone #: 77-249-170...

All S4 partners are required to provide pre-sales engineering support and 1st level technical support to their dealers and integrators. For Schneider Electric dealers and branches the best way to request this support is to email the problem or assistance request details into the Product Support (PSS) queue directly:

product.support@schneider-electric.com

Alternatively, there are different dial-in numbers people can use to log a new case (one for each of the three different cities where PSS is located).

Emailing this address (or calling in and dictating your case details to the person manning the phone) starts the process. PSS will facilitate any necessary escalation within the Schneider Electric support organizations or to The S4 Group.

You have two options:
1) Run the configure wizard again, or
2) Manually add the device

If you manually add the missing devices you have to do 4 steps for each one
1) Add the device to the correct physical network

2) Add the device to the Building Control Network (BCN)

3) On the Physical Device tab in the BCN object link the two together

4) Now, manually select the correct Device Template to the object in the BCN

If there has been a history of devices going off line in the pure Metasys environment it is a sign that something is wrong.

• It could be bad wiring,

• it could be too many N2 devices on the bus,

• it could be EMF,

• it could be a bad transmitter on a N2 device,

• it could be multiple masters accidentally installed on the bus.

Determine the issue and correct it before proceeding with the integration.

Metasys Integrators, MIG, was used by JCI to integrate devices with serial interfaces into Metasys. These configurations were all developed and provided by JCI. The MIG has its own unique configuration file. Sometimes you will find that JCI provided a .DDL file containing the point list. In other cases a Device Type Template needs to be generated for each Vendor Device from hard copy point list documentation.

The N2 protocol specification only reserved a single device code for MIG devices. Therefore, the Configuration Wizard cannot determine the manufacturer, application, or any configuration details about the attached device. All that we can tell by looking at the device from the N2 bus is that it is a MIG. We get no indication of what type of equipment is attached to the MIG. It is a simple task to assign an appropriate Device Type Template to a MIG after the completion of the Configure Wizard.

As we encounter these at customer sites the resulting Device Type...

• Some align themselves with specific BAS manufacturers; some support a large line of products.
• JCI has moved away from the Iconics platform and left lots of M3 and M5 Workstation customers stranded. There is a potentially huge market to migrate these customers to the commercially available Iconics Genesis32 product and porting the graphics from the M3 or M5 workstation to this system.
• Ask for the person responsible for 3^rd party product integration or integration to Johnson Controls Metasys^® Building Automation Systems.

Yes. However, it takes more work than for the application specific controller applications. Consider the existence of Point Multiplexor applications a Yellow flag when preparing for an integration. It says that there is probably a lot of logic in the NCM driving the points in these devices.

The normal designed operation of the Metasys N2 DDC controllers is that if they lose communication with their supervisory controller (NCM, Facilitator, Companion, N30, NAE, Facility Explorer) they will continue operating the building utilizing the last available values or default values for all parameters, etc. For instance, Outside Air Temperature is typically a global variable that is distributed by the supervisory controller to all N2 devices that need the information. If the supervisory controlle fails, or communications to it via the N2 bus are lost, the individual controllers will continue operating with the best information they that have available.

If N2 devices are ...

The chassis based Metasys system came in multiple configurations. The most common were 5-slot chassis and 3-slot chassis. The 5-slot system was known as a Network Control Unit because it would support a NCM card as well as modular I/O cards. The 3-slot chassis supported only modular IO cards and therefore was called a Network Expansion Unit, or NEU.

When JCI migrated to the stand-alone NCM many times they simply removed the NCM card from the NCU chassis and turned it into the equivalent of a NEU as a migration strategy. When they did this the logic driving the modular IO cards had to be re-implemented in the NCM.

The modular IO cards, including the DCM,  in either a NEU or a converted NCU are accessible to the N2 bus and can be integrated utilizing the S4 Open appliances (OPC-N2 Router and BACnet-N2 Router). However, the logic driving those IO points still resides in the NCM. So, the new head end either has to co-exist with the legacy NCM or the logic in t...

The DSC8500 system pre-dates Metasys and does not use the N2 protocol. Therefore, our S4 Open Appliances (OPC-N2 Router and BACnet-N2 Router) do not support them.

We did do some market analysis and could not find enough demand for us to invest in reverse engineering the DSC8500 protocol and developing a product on speculation. It is doubtful that we could recover our engineering and development investment. The biggest concern that I heard from potential customers was that there is not enough expected useful life left in these systems for customers to invest in an integration solution. What I’ve heard is that the systems are so old that they can no longer be maintained and that the preferred approach is to replace these systems with newer technology.

In fact, we look at each possible new integration project in this same way. We have to answer the following questions:

• Is there enought useful life left in the legacy systems?

• Can the legacy system...

There are SIGNIFICANT advantages to doing an integration instead of a compete replacement.

• Integration to legacy field devices can save up to 90% of the cost of doing a complete replacement. This becomes more evident as the size and complexity of the building increases.

• If you do a phased replacement the customer can include the incremental transition costs in their maintenance budget. They do not have to do a onetime large capital outlay.

• By integrating and replacing the head end they gain most of the same benefits of a complete replacement day one.

• Make sure that you are looking at the complete cost of a replacement system. It’s not just the hardware. All of the installation and commissioning services need to be considered.

Repeaters work at the RS-485 electrical level to amplify the signal and nullify the effects of noise and distortion on the signal. In effect, they take a signal in, amplify it, and retransmit it almost perfectly with any distortion removed.

Like any electronic device repeaters can deteriorate with age. When you are doing an integration with the S4 Open appliance this is one of the things to check for. If you find a repeater in a N2 bus this may provide a perfect place to split the bus in two in order to improve performance.

• bringing both segments into separate downstream N2 ports of a S4 Open appliance (OPC-N2 Router or BACnet-N2 Router) will lower the load on each segmant, improve error handling and resiliance of the bus, and somewhat improve performance.

• bringing each segment into its own S4 Open appliance will do all the above and significantly improve overall preformance. In addition, it provides a more distributed solution that is less dependent on ...

We've seen a lot of N2 installations where the Metasys supervisory controllers were installed at a central location with N2 bus risers to each floor. Our recommendation is to eliminate those long runs whenever possible. The longer the N2 bus is the more suseptable it is to EMF and other formas of interference.

If, there is Ethernet connectivity throughout the building install the S4 Open Appliance (OPC-N2 Router or BACnet-N2 Router) as close to the first N2 device as you can. At that point connect to the Ethernet backbone where there will be high speed capabilitiesnd error detection and correction provided as part of the network.

You can use the ComBus Quick Tester, a digital volt meter, or similar tool to test the N2 bus. In order to perform the test you need to disconnect it from the supervisory controller. If using the ComBus Quick Tester you simply plug the Phoenix Contact connector into the tester and start the process. If using a digital volt meter you need to measure the voltages between each of the legs of the N2 bus.

According to the documentation that comes with the ComBus Quick Tester the guidelines for a successful test are:

• to Ref VDC 2.45 -3.00 will pass

• to Ref VDC 1.90 - 2.54 will pass

• to - VDC 0.38 - 0.92 will pass

The N2 protocol was defined by Johnson Controls for the Metasys system. It was based on the OPTO-22 optimux protocol but over its life was extended may times.

The N2 Open protocol definition was published by JCI for 3rd parties to be able to natively support the N2 Open protocol in their devices. The JCI UNT, AHU, and VAV controllers support this same protocol.

N2 was extended with the System-91 protocol to support System-91 devices like the DX-9100.

N2 was again extended with the N2B variant to support VMA devices.

All of the variations of the N2 protocol will co-exist on the same wire and all generations of Metasys supervisory controllers can talk to all N2 devices. Our S4 Open appliances will work with any device that is compliant with the N2 protocol specification.  Many competing integrations only implement the N2 Open protocol.

Is N2 a standard? JCI did a very good job at marketing their Metasys Compatibility program ...

JCI Engineering guidelines recommended

• A maximum of 50 N2 devices if the supervisory controller is a N30.

• A maximum of 100 N2 devices if the supervisory controller is a NCM.

They also recommend that you reduce the number of devices if any of them are VMA or DX-9100 devices. These devices require more bandwidth than the N2 Open devices.

The N2 protocol definition provides 256 addresses. 0, 254, and 255 are reserved for JCI use. So, you have 253 assignable N2 addresses. If you find a legacy installation with more that the recommended number of N2 devices installed you should consider splitting it into multiple N2 buses. Remember, you will soon be driving the legacy N2 bus from either OPC or BACnet transactions coming in at Ethernet speeds!

For more details on this topic visit the JCI web site and search for documents related to the N2 bus. They have some very good reference documentation.

BAS Manufacturers include Advantech, American Auto-Matrix, ASI Controls, Honeywell, Johnson Controls, KMC Controls, Reliable Controls, Siemens, Tridium, etc. These manufactures all have their own HMI.

1. Most have migrated to the BACnet communications protocol standard so they would be candidates for the S4 Open: BACnet-N2 Router.
2. ASI Controls and Advantech use the OPC communications protocol standard so they would be candidates for the S4 Open: OPC-N2 Router.
3. Ask for the person responsible for 3rd party product integration or integration to Johnson Controls Metasys Building Automation Systems.
4. S4 reserves the relationships with BAS manufacturers, even when there are in one of our partner's sales territory. Some of the manufacturers have established OEM arrangements, private labelling arrangements, or preferred supplier agreements for their channel partners.
5. Think outside the box when talking to these organizations. They may have ideas of their own about how we c...

Vendor devices, VND, do not have a configuration file. Sometimes you will find that the vendor provided a .PRN or .DDL file containing the point list. In other cases a Device Type Template needs to be generated for each Vendor Device from hard copy point list documentation.

The N2 protocol specification only reserved a single device code for Vendor devices. Therefore, the Configuration Wizard cannot determine the manufacturer, application, or any configuration details about the vendor device. All that we can tell by looking at the device from the N2 bus is that it is a Vendor device. It is a simple task to assign an appropriate Device Type Template to a VND device after the completion of the Configure Wizard.

Vendor, or VND, devices are 3rd party devices whose manufacturer has implemented the N2 Open protocol in the device. Typically, this was done through the Johnson Controls Metasys Compatibility Program.

As we encounter these at customer sites the...

We've seen multiple areas where improvements can be made in existing N2 buses. From an electrical point of view the N2 bus follows the RS-485 standard with a N2+, N2-, and reference line. In many cases we will point you back to JCI documentation for details. We're not going to try to re-engineer the N2 bus technology. It is what it is.

We have seen many cases where either improper installations or just normal wear and tear over the years has taken its toll. It's also a fact that once you integrate to a legacy N2 bus with either the OPC-N2 Router or the BACnet-N2 Router it will be driven harder than it has ever been driven before. If anything is marginal, it will be exposed by the additional load put onto the system.

We always advise our integration partners to validate the N2 bus as part of determining the scope of an integration project. In fact, we advise them to specify in their contract that the customer deliver to them an in-spec and working N2 bus with wo...

It is very important to validate that the N2 bus is within specs as part of the planning for a N2 integration. The N2 bus is based on the RS-485 specification.

Some JCI N2 devices have a termination switch, others have a self termination capability.  Research the JCI documentation carefully before assuming that the end of each N2 bus segment needs termination.

When you remove a legacy supervisory controller from the N2 bus it may have been providing termination that needs to be replaced to keep the bus operating within spec.

The more information you have at hand the less risky a N2 integration will be and the more successful the project will be. In preparation for a N2 integration we always recommend that you:

• Use HVAC Pro and create a Network Map report with it. This will tell you the hardware type, Firmware versions, and application loaded into each N2 device.

• If you see any Generic IO / Point Multiplexor applications this is a red flag. That means that the logic driving those points is back in an NCM, or other supervisory controller. You can still do a very successful integration. You just need to do more planning.

• Make sure that each N2 bus segment is within electrical specifications. You can use the ComBus Quick Tester or a DVM. You will be driving the N2 bus harder than it has ever been driven before so any weakness will come out.

• Review as built drawings and any other documentation that is available for the Metasys installation. I've taken the approach of s...

When we designed the S4 Open Appliances we determined that we would stop short of providing these services. Johnson Controls has very effective tools for performing these functions that are aware of all of the variations in firmware, application revisions, etc. We didn't feel that we could add any value in this area.

Use HVAC Pro for N2 Open devices like the UNT, VAV, and AHU

Use HVAC Pro for the VMA

Use GX-9100 for the DX-9100

One of the things that we did include in the design is the ability to easily determine the application loaded into N2 devices, the firmware version running in the device, the original configuration file name, etc. This information is provided on the properties page for each device in the Building Control Network, BCN, folder. The information provided by each device type varies. Details for many N2 devices are provided now. Others will be added in the future as time and resources allow.

If you find legacy Metasys Fire panels at a site you should seriously consider replacing this panel with current generation technology.

They probably make heavy use of the Metasys global database, communications between NCMs via the N1 bus, and could have special algorithms loaded in them to shut down air handlers, pressurize adjacent areas to a fire incident to prevent smoke damage, and reverse the fans to pull smoke out of the building after a fire incident is cleared. All of these things need to be analyzed as part of the up front integration planning. The logic in all NCMs in the building needs to be carefully analyzed and adjusted as appropriate.

These buildings can still be a very successful integration project as long as you understand up front what you are getting into and plan accordingly.

We developed the concept of Device Type Templates so that we would not have to rely on Metasys configuration files being either available, or up to date. They also expose more points than Metasys typically would. For instance PID loop tuning parameters and other parameters that would normally only be exposed by the Metasys configuration utilities are exposed so that 3rd party tuning and continuous commissioning applications can be utilized for a Metasys system.

As background, here’s the process that we use in the Configure wizard to try to find the best match with point mapping. N2 devices are interrogated to determine their hardware type and the application loaded into them.

1) Best case – we have a Device Type Template that matches both the hardware type and the application loaded into device. We refer to these as Application Specific Device Type Templates.

2) Next best – we match on the hardware type but not the application. We assign a generic point map ...

We have developed Device Type Templates for all currently in production Metasys N2 devices. Some of the earliest N2 devices have been obsolete for quite some time and any remaing early generation products are likely candidates for replacement during the integration process. In these cases we are not developing Device Type Templates until we find actual customer projects needing these devices supported. In most cases a new Device Type Template can be created within a couple of days as long as documentation can be found for the device and its point list. Examples of where we have recently added Device Type Templates for these older devices include:

• the LCP, the Lab and Central Plant Controller or DC-9100. This was a predicessor to the DX-9100

• the DR-9100 Room Controller. This was a predicessor to the TC-9100.

The VAV Modular Assembly, VMA, was one of the last device families to receive support in the S4 Open Appliances. These devices utilize their own variation of the N2 protocol referred to as N2B. With this work completed we support all variations of the N2 protocol and any N2 device that could be found on a N2 bus.

N1 is the JCI proprietary system level protocol that JCI used to talk between NCMs and to their workstations. We deccided to integrate at the N2 field bus level because you have more degrees of freedom to get to all points on the N2 field devices, including those used for commissioning and tuning. At the N2 level you do not need to pass through the Metasys database and security imposed by the NCM.

If there is enough of a market potential we would consider developing a N1 integration in the future. Having a N1 to OPC or N1 to BACnet capability would

• allow you to integrate to the early Metasys chassis based systems without needing to pull the NCM cards out of the chassis. However, most of these systems have been upgraded to stand alone NCM supervisory controllers or moved forward to the NAE based systems.

• allow you to access information that is calculated or stored in the NCM. Most of this is typically replaced by new head end systems during the integratio...

Centaurus Integrators, CIG, was used by JCI to integrate devices that had more complex interfaces than could be handled by the MIG into Metasys. From a technical standpoint these devices look like a Vendor, VND, device on the N2 bus.  These configurations were all developed and provided by JCI, or Bob Caldwall and his team at Centaurus Systems before they were purchased by JCI.

The N2 protocol specification only reserved a single device code for VND devices. Therefore, the Configuration Wizard cannot determine the manufacturer, application, or any configuration details about the attached device. All that we can tell by looking at the device from the N2 bus is that it is a VND device. We get no indication of what type of equipment is attached to the CIG. It is a simple task to assign an appropriate Device Type Template to a CIG after the completion of the Configure Wizard.

As we encounter these at customer sites the resulting Device Type Template is added t...

No. We recommend teaming with independent contractors, ABCS organizations, or JCI branches for Metasys expertise, Here’s why.

S4 expertise is in networking/telecommunications, system integration, and software engineering. Our training and support reflects this. We primarily focus on how our product works and how it integrates into the Metasys system.

• We certainly understand the Metasys system architecture, the protocols, and how to use the Metasys utilities to set up tests in our lab for development testing, QA, and customer demos.

• We do not advise our customers how to program and commission the Metasys field devices, or supervisory controllers, in production installations.

We focus on what we do best and enlist others to supplement our own skills:

• We have a strategic partnership with Obermeier Software of Verl, Germany for software development and hardware / software integration.
• We have carefully architected the products so that each feature that we develop is reusable in a Lego-like manner. This maximizes our ability to make each product enhancement quickly available to all members of the S4 Open product family and minimizes our support cost because the code base for each feature is only maintained in one place.
• We made the strategic decision early on not to be in the hardware design and development business. All of our products are hosted on commercially available, highly reliable industrial PCs.
• We also made the decision that our products would be delivered as network appliances. That is, a fully integrated bundle that includes hardware, pre-installed software, and wizards to aid the installer with system setup and commissioning...

Steve Jones is managing partner (more formally owner and president) of the corporation. Steve’s bio can be found in the About Us area of the site.

There are multiple classes of potential customers, and sale influencers, that you may run into. Check their web site to get a feeling for the type of company they are before calling on them and adjust your presentation accordingly.

BACnet product manufacturers

• There are a few companies out there who specialize in BACnet products but are not themselves a BAS manufacturer. SCADA Engine in Australia is one example.
• Ask for the person responsible for 3rd party product integration.

Metasys® 3rd party product vendors

• These are companies who manufacture mechanical systems, electrical systems, or controls who have implemented the JCI proprietary N2 field bus protocol in order to be compatible with Metasys®. Within the JCI Metasys® world these are called VND devices.
• Our play here is in providing either the S4 Open: OPC-N2 Router or the S4 Open: BACnet-N2 Router in large existing installations of their products to provide a gateway to open protocols. Typical...

Some of these deal with controls, some of them subcontract the controls to someone else.

Ask for the person responsible for Building Automation Controls

Not today. This is a planned future capability. There are several things underway that will lay the groundwork for being able to support this.

• BACnet IP downstream. The ability to utilize BACnet IP as a Downstream interface to the S4 Open appliances.

• BACnet device discovery: The ability to treat BACnet interfaces like a downstream interface to the S4 Open appliances.

• BACnet MS/TP support. The ability to utilize BACnet MS/TP as a source for either Upstream or Downstream interfaces.

• N2 VND device emulation. The ability to make discovered devices look like Vendor, VND, devices on the N2 bus.

• .PRN file creation. The ability to create a .PRN file from any discovered devices.

When all of these components are in place we will be able to publish MS/TP devices to any supported upstream interface including N2, BACnet IP, OPC, and any others that we add support for.

Not today. This is a project that is in progress.

• Today we support an OPC Server interface.

• We need to add an OPC Client interface.

• We need to add an OPC discovery capability.

Once these items are in place we will be able to publish OPC devices to any supported Upstream interface.

Not today. This is a project that is in progress.

• We need to ad an upstream SNMP interface. This will allow us to act as an SNMP proxy agent and publish to SNMP enterprise managers.

• We need to add a SNMP Manager interface. This will allow us to talk to SNMP devices on the network.

• We need to add a SNMP discovery capability.

Once these items are in place we will be able to publish SNMP devices to any supported Upstream interface.

We have established a N2 test bed that can be utilized to perform interoperability testing with any BACnet or OPC client, device, or application. We establish a virtual machine environemnt for each manufacturer environment. Depending on the requirements this is either Microsoft Virtual PC or VMWare. Initially, this is utilized for establishing compatibility between S4 products and any other manufacturer product. Longer term, this same environment is utilized for customer demonstrations and ongoing support of customer installations.

One of the reasons that we went to these lengths is that we understand that very few organizations have a complete N2 test environment. Our testbed can be made available through remote access technology for support of mutual customers and ongoing regression testing when new products, or product upgrades, are released. Most of the BAS manufacturers have provided evaluation copies of their products to support these testing efforts.

Ple...

Design-Build contractors do everything from the cradle to grave for new building construction or renovations.

1. Our primary play here is with renovations.
2. Ask for the person responsible for Building Automation Systems. If the existing building has the Johnson Controls Metasys^{<span lang="EN-IE" style="font-family: &amp;quot;Arial&amp;quot;,&amp;quot;sans-serif&amp;quot;; mso-bidi-font-size: 12.0pt;">®</span>} Building Automation System we can provide them the technology to upgrade the head end of the system and salvage the existing field devices.

1. Create the device in the physical network in which it resides (network n -> new -> field device)
2. The "Define Physical Device" window will open; assign the N2 address for this device
3. The device should now appear under the correct N2 network
4. Now create a device object in the Building Control Network. Specify the N2 address that you want the device published to in the Upstream N2 network. (BCN -> New -> Device...)
5. Link this object to the Physical Field Device you created in the physical network
6. Assign the appropriate device type template for this device&nbsp;
7. The device is now integrated into the system and can be discovered by your BACnet client

All of our software is written in “C” code with the intent of keeping the code a portable as possible. The OS is Microsoft’s CE 5.0 which gives us near real time performance and an additional layer if insulation from the actual hardware. We’ve stuck with one hardware platform and OS to minimize support requirements but, if the right business case were made, we could port the software to other environments.

This is the inverse of what our products do today. The S4 Open Appliances integrate into a N2 bus and publish what they find to open OPC or BACnet environments.

Future enhancements will consider making SNMP, OPC, BACnet IP, BACnet MS/TP, Modbus, EnOcean wireless and other devices available to legacy JCI Metasys supervisory controllers via the N2 interface.

The Metasys N2 bus follows the RS-485 standard for its physical and electrical characteristics. It runs at 9600 BD, half duplex using N2+, N2-, and Ref wires. Our S4 Open appliances are pre-configured to have all Com ports operate in RS-485 mode.

If you run any of the JCI Metasys configuration or commissioning tools HVAC Pro, GX-9100, etc. from your labtop or another Windows PC and want them to communicate the the N2 bus via their COM port you'll have to utilize either a USB to RS-485 or a RS-232 to RS-485 converter.

We&nbsp;have been using RS-485 converters from B&B Electronics www.bb-elec.com to connect our PCs to the N2 bus.

For RS-232 to RS-485&nbsp;we use their model 485SD9TB

For USB to RS-485 (N2 bus)&nbsp;we use their model number 485USBTB-2W

The USB Serial Port technology has become so standardized that most manufacturers' products should work fine although the B&B products are the only ones we have tested. Note that you may have to a...

Only if we find that we can make a business case for it. N1 is only applicable to Metasys installations utilizing the NCM supervisory controller. These are becoming less in number all the time. All of the data in the field devices can be accessed through our OPC-N2 Router or BACnet-N2 Router products while keeping the NCM in place.&nbsp;So, there appears to be very little value add to developing a N1 integration.

If you disagree let me know. If you can make the business case we'll develop the product.

With version 1.3 of the S4 Open: BACnet-N2 Router we support both confirmed and unconfirmed COV subscriptions and associated notification.

In addition, we have added a Transparent Caching service to the BACnet-N2 router to disconnect the BACnet protocol from dependence on direct access to the N2 bus. The BACnet-N2 Router responds to BACnet requests from its cache resulting in almost immediate response.

The JCI design of the N2 bus is fixed at 9600 Bd. We have to live with that. It can’t be changed.

So, the problem becomes how do we accommodate BACnet IP or OPC transactions coming in at Ethernet speeds?

• Transparent Caching and BACnet COV support improve efficiency

• Validating the N2 bus, repairing any installation problems, and removing sources of electrical interference improve performance

• Breaking the N2 bus into smaller segments distributes the load. Each segment may come into a separate Downstream N2 Interface on a N2 Router or each one come into a separate N2 Router

• Poll rates may need to be adjusted to frequencies more realistic for the capabilities of the N2 bus

As our integration partners have been digging into some of the older Metasys® installations they are finding Generic IO / Point Multiplexor applications much more frequently than I thought they would.

You can still do a very successful integration with these devices but it may take a bit more planning than if they were loaded with more traditional Metasys® applications.

• You can process the .PRN Metasys configuration (resource) file for these devices through the S4 Configuration File Conversion Utility to create a custom device template

• You may need to investigate custom logic in the Metasys supervisory controller. For the NCM this would be GPL or JC Basic logic.

• You may be able to determine how the points are used by investigating the assignment and presentation of points in the Metasys Operator Workstation

• You can investigate Single Side Loop logic, Interlocks, etc. programmed into the N2 device itself utilizing HVAC Pro

All of the S4 Open appliances include a 1-year Software Assurrance program that provides all maintenance fixes and minor enhancements released during the time it is in effect. You can subscribe for additional years of coverage. The hardware warranty is passed to our customers from our hardware platform supplier, Advantech. The product used to host S4 Appliances at version 1.5 and earlieris the Advantech UNO 2059GL platform.

Advantech hardware warranty information from their web site http://www.advantech.com.

Standard products manufactured by ADVANTECH carry a 2 year global warranty. Excluding non-Advantech commodity items such as the LCD, hard drive and memory, etc and custom outsourced products. Warranty on-line information is only available for the product name as listed on the invoice. No on-line warranty information is available for the product name sub-components, modules, parts or peripherals. The Advantech gl...

This product was never put into production but could be made available as a special request.

N2 Switch Functionality:
- Merges multiple legacy N2 buses into a single Upstream N2 bus
- Performs automatic N2 address translation
- Works purely in the N2 domain. Does not publish to any other interfaces (OPC, BACnet, etc.)

Contact The S4 Group for a quote.

Most N2 devices do not contain a time of day clock that you can access directly. They do have an on-board clock that can be synchronized with the head end and is used as a fallback when the N2 device becomes disconncted from the head end. In normal operation they completely rely on a supervisory controller to tell them if they should be in Occupied or UnOccupied mode by toggling a binary point.

Typically, you’ll see set points for Occupied mode and another pair for UnOccupied mode. Simply have&nbsp;your new HMI&nbsp;or another (BACnet or OPC&nbsp;as appropriate)&nbsp;controller toggle the Occupied point in each N2 device to indicate the mode that you want each controller to operate in.

Check the manufacturer documentation for each N2 device and application supported by it for the correct point to toggle the Occupied / UnOccupied status of the device and the point names assigned for the setpoints.

Yes. Emulation of N2 devices as a virtual BACnet device includes full support for the BACnet priority array. BACnet expects devices to honor the Priority Array functionality so the BACnet-N2 Router acts as a proxy for the N2 devices and emulates a Priority Array for each point were the BACnet standard defines Priority Array support.

• BACnet clients can utilize the BACnet priority array as they would with any BACnet device.

• The "Supervisory Controller As A BACnet Client" option enables the Metasys supervisory controller to participate in the priority array functionality

• Priority array emulation can be disabled for any point that needs to give direct control of the present value to the BACnet client

• The N2 bus and N2 devices were not developed with the BACnet concept of a Priority Array. Therefore, each N2 command is executed as soon as it is presented to the N2 bus and is recognized by the target device. The S4 Open Appliances give the integrator complete control o...

One of the most important aspects of a successful Metasys integration is in taking the time to understand the existing N2 devices and their configurations.

• HVAC Pro is the Metasys configuration and commissioning utility used for N2 Open devices like Unitary Controllers (UNT), AHU, and VAV controllers. It is also used for the VAV Modular Assembly (VMA) devices.

• GX9100 is utilized to program and commission the DX-9100 device.

These utilities are available as part of the M-Tools package through authorized Metasys distributors. There are frequent discussions about acquiring, installing, and working with these utilities on the HVAC Talk forum, http://www.hvac-talk.com.

You can also purchase the M-Tools package through The S4 Group.

This utility automatically created Alerton Envision Device Templates and Display Templates utilized by Envision projects.

Support for this utility is now discontinued as it is no longer needed since the S4 Open: BACnet-N2 Router now publishes each N2 device as an emulated BACnet device under a Virtual BACnet Network. Standard Envision template technology can now be used with the N2 integration.

S4 Open Appliances support both automatically assigned and static IP addresses. Configuration is through a tab on the S4 Open Management Console Ethernet Properties page.

This question was originally posted on the HVAC-Talk forum by T87F

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I have a "S4 Open: BACnet-N2 Router" working at a school. They had a power failure for about two hours over the weekend. The S4 router lost its IP address settings, it reverted back to the default settings. I reset the IP address and it works fine now. I wounder why the S4 router lost its custom IP address after a power failure. I will most likely add a UPS for this router in the future.

Response:

You can contact us any time that you need support. The UPS is always a good idea as an additional precaution. Without knowing the details here is the most likely scenario of what happened. The S4 Open Appliances are hosted on an industrial PC running Windows CE.CE runs in memory after it is booted from the CF card. This includes ...

This is a perfect example of why we advise our integrator partners that they need to have Metasys experience available before starting an integration project. The bottom line here is that the logic in the N2 device itself has the final say about what actions&nbsp;will be allowed.

One of our integration partners&nbsp;were seeing unexpected results when trying to write to a the Occupied Command point on a N2 device.

There are four basic operations that can be performed against a point on a N2 device: N2 Read, N2 Write, N2 Override, and N2 Release. Our Device Templates give you complete control over what command is sent to the N2 point. N2 Override trumps N2 Write.

In order for the S4 Open&nbsp;Appliances to function they need to be inserted between the&nbsp;Metasys supervisory controller and the N2 field devices. With the&nbsp;1st generation Metasys chassis based Network Control Unit (NCU) this is not physically possible because all cards sit on the chassis backplane.&nbsp;This includes both NCM and Modular I/O cards. Considering the age of these systems, and the difficulty of repairing them, we are recommending&nbsp;that you approach these systems with a co-existance and phase out strategy. This way we you can&nbsp;move forward with an integration project with minimal investment and even less risk. Please refer to this diagram.

In&nbsp;order to keep the picture as simple as possible&nbsp;we showed all network connections as Ethernet. If the NCU has ARCnet then it, and whatever Metasys workstation is associated with it, would reside on a separate ARC...

You can find most of our brochures, documentation, and presentations in the public Dropbox folder https://www.dropbox.com/sh/yqfepqsb9omu10f/AAAOOR42Kp0K6XeZai64eI0Sa?dl=0.

Case studies can be found on our web site at http://www.thes4group.com/case-studies.

Additional Comments
Refer to The S4 Group web site http://www.thes4group.com product pages for product details, articles, FAQs, etc.

Device Templates define point mappings in our S4 Open Appliances. For each defined point the Source String defines the point address on the N2 bus. Optional parameters .Value, .Override, and .Release force the N2 write transactions to be handled as a normal N2 Write, a N2 Override, or a N2 Release command. Read operations always return the N2 present value of a point.

Default actions if no parameter is specified are:
- N2 Override for physical I/O points.
- N2 Write for internal points.

Additional Comments
It is important to note that the address space created by our device type templates is independent from the configuration in the Metasys supervisory controller configuration database. Device Templates can be changed at will without impacting the operation of the Metasys head end.

The Metasys priority structure is implemented within the Metasys supervisory controller. Commands submitted to the N2 bus are executed in the sequence that they are submitted. i.e. on the N2 b...

This utility converts Metasys .PRN or .DMO files to custom S4 Device Templates. It is available only to partners of The S4 Group for use in supporting their integration projects with one of our S4 Open Appliances. Contact The S4 Group, Inc., or your distributor, for details.

Additional Comments
This will download and install the utility on your PC. If the Internet is accessible when you use the application in the future any available updates will automatically be installed.

Access the Configuration File Conversion Utility at URL
http://www.thes4group.com/ClickOnce/S4FileConverter/publish.htm

Note that the URL is case sensitive. If you type it in manually it must be EXACTLY as it is provided.

The S4 Group is a software and network appliance developer that specializes in products and associated services for two markets.
1. The S4 Open product line addresses Building Automation integration to open environments.
2. The Obermeier Software SNMP OPC Gateway products address integration of Industrial Automation and Process Control (generically non-IT) systems to, and from, enterprise environments.

Following is a list of organizations who we know have the ability to provide Metasys® support. The one who is right for your organization might depend on exactly what kind of support you need and your geographic location. When you contact these organizations please tell them that the contact was initiated by a referral from The S4 Group.

Bob Caldwell
Owner
Centaurus Prime
4425 Cass St., Suites B-C
...

The honest answer is that it depends.
- On the condition the existing Metasys system and N2 bus
- On how much expertise your installation team has about Metasys and N2 devices
- On how much expertise your installation team has with the upstream protocol (i.e. OPC or BACnet)
- On the number of N2 devices you are integrating
- On your election to use the Upstream N2 Interface to co-exist with a legacy Metasys supervisory controller
- On how much custom programming you will need to deal with
- On the skill levels of your team working on the project

Additional Comments
We can give you some general guidelines. You’ll need to extrapolate from there
- Assume that everything you need to do to bring your own brand of field device into your operator workstation you will need to do for Metasys devices
- Plan on using either the ComBus Quick Tester or the S2 device to validate the N2 bus on each network before you start the integration. A...

This procedure details how to restore a saved automation.net.xml configuration file to an S4 Open Appliance

Use the smallest USB thumb drive that you have available. Delete all files on the thumb drive. The drive must initialize fast enough to be recognized during the startup sequence of the S4 Open Appliance.

Step 1: create a folder in the root of your USB Thumb Drive named \DNA
Step 2: Place your configuration file backup into this folder. If necessary, rename it to automation.net.xml.
Step 3: Create a “trigger” file on the root of the USB drive named updatedna. The file name should not have an extension on it. i.e. 'updatedna.txt' will not work. The content of the file is not important. All we look for is the existence of a file with this name.
Step 4: Insert the USB thumb drive into the S4 Open Appliance and reboot the system. You can do this by power cycling the system or through a Reboot request in the S4 Open Management Console. When it comes back up you will have t...

We have modified our order processing system to have pre-defined system bundles. The bundle name is the first line that you see for each system configuration in our quotes, sales orders, etc. That has eliminated a huge number of configuration issues and questions during the ordering process. This bundle contains the power supplies, cables, etc. that are need for a complete system solution. We still offer individual parts in case they are needed but this approach greatly streamline things.

Here is how the part name is interpreted:

{{image:118, rendition:i822, position:left}}

In your quote the lines following the bundle name define the components needed to complete this bundle.

1. Determine the interface that you need to publish to. OPC and BACnet IP are available.
2. Determine the interface that you need to integrate to. Metasys N2 is the only current Downstream Interface option.
3. Determine how many N2 devices are on the N2 bus. Each assigned N2 address must be counted, included those assigned to XT devices on the DX-9100 expansion bus. JCI’s engineering guidelines state that for a N30 supervisory controller you should have at most 50 N2 devices on the bus and for a NCM at most 100. They go on to say that DX9100 devices and VMA devices should each count as 2 when calculating the number of devices that the N2 bus will support.
4. Determine if you need to use the Upstream N2 interface. This enables the ability to co-exist with the legacy supervisory controller. The Upstream N2 interface is compatible with any generation Metasys supervisory controller as long as it supports the N2 protocol.
5. Determine if you need multipl...

This is a special order item offered only to high volume distributors and strategic partners who are investing in a permanent demo / training facility or portable demo to assist in marketing and sales efforts.

Order part number S4O-DemoKit-S

Additional Comments
The Demo Kit includes a full size S4 Open Appliance at S4 subsidized price of $1000.00 U.S.

The S4 Partner is responsible for all shipping costs, VAT, fees, duties, or taxes imposed by the destination jurisdiction.

The system will be pre-loaded with the S4 Open: BACnet-N2 Router-N256-D1-U1 or S4 Open: OPC-N2 Router-N256-D1-U1 as requested. This selection can be changed in the field as needed.

Power supplies, cables, adapters, support CD, and the S4 Open Management Console are included.

Software Assurance will be provided as long as this system is utilized as a demo / training platform.

The system is restricted to be used for demo / training purposes only. If it is deployed into a production environ...

The N2 bus and N2 devices were developed long before the definition of the BACnet protocol and the concept of a Priority Array. Therefore, each N2 command is executed as soon as it is presented to the N2 bus and is recognized by the target device. N2 devices have four basic commands that they support: N2 Read, N2 Write, N2 Override, and N2 Release.

However, BACnet expects devices to honor the Priority Array concept so the BACnet-N2 Router acts as a proxy for the N2 devices and emulates a Priority Array for them. From the standpoint of a BACnet client or device wanting to talk to a N2 device via the S4 Open: BACnet-N2 Router it can utilize all features of a BACnet Priority Array.

The S4 Group has a Strategic Supplier relationship with Honeywell. If you are a Honeywell branch or dealer, S4 Open Appliances and accessories can be ordered using Hubwoo. If Hubwoo is not available in your country please check with your Country Manager to make alternate arrangements.

Procedure
Part numbers in the Hubwoo system will be very similar to the standard S4 part numbers.
- In Hubwoo search for part numbers using the search string S4O* i.e. S Four(4) Open.
- Check the comments for each part number and look for those that indicate they are a complete system package. This should be the preferred method of ordering. The system packages, or bundles,
provide you all the components needed for a complete installation. Individual parts should only be ordered to support field upgrades or special cases.

Your purchases will be drop shipped from The S4 Group. Make sure that you provide any supplemental information required for the shipping service. By default orders will ...

The S4 Group has a Strategic Supplier relationship with Schneider Electric. If you are a Schneider Electric U.S. based branch or dealer S4 Open Appliances and accessories can be ordered using iPortal. Outside of the U.S. you should check with your Country Manager for the appropriate procedures.

Procedure
Part numbers in the iPortal system will be very similar to the standard S4 part numbers.
- In iPortal the part numbers will be prefixed by SFG. i.e. S Four(4) Group.
- The suffix -s on our S4 part numbers designates a complete system package. This should be the preferred method of ordering. Individual parts should only be ordered to support field upgrades or
special cases.

Your purchases will be drop shipped from The S4 Group. Make sure that you provide the supplemental information required for the shipping service. By default orders will be shipped by UPS Ground. Please specify if you require shipping by another carrier or expedited shipping.

Additional Comments
Yo...

The N2 bus is loosely based on the RS-485 standard. The design of the NCM allowed it to compensate for power drops, bad wiring practices, and interference without the need to add a repeater every 32 devices as indicated by the RS-485 standard. The other situation that could cause similar symptoms is that repeaters, like any electronic device, deteriorate with age and could fail to provide the desired boost to the N2 network.

Solution
Measure voltage drops at various points on the N2 bus and insert or replace repeaters where indicated to guarantee reliable performance of the bus.
Additional Comments
Our integrator partners have had good experiences with the B&B 485OPDRI. See http://www.bb-elec.com/Products/Serial-Connectivity/Isolators-Repeaters/Optically-Isolated-RS-422-485-Repeaters.aspx

This article documents lessons learned and best practices for performing integrations utilizing the S4 Open: BACnet-N2 Router and Tridium, or Niagara, systems. Testing was a cooperative effort between The S4 Group and Tridium. This guidance is appropriate for versions of The S4 Open: BACnet-N2 Router prior to firmware release 1.22.

BACnet devices can act as either a client or a server depending on the function that they are performing at any given point in time. When acting as a client a BACnet device will use its own APDU Timeout, APDU Segment Timeout, and Number of APDU Retries to manage the communications between itself and any other BACnet devices it is communicating with. There is no absolute correct settings for these properties so the installer needs to adjust them to reflect the conditions presented by each installation.

In this integration the Tridium system is acting as a BACnet client and the S4 Open: BACnet-N2 Router is acting as a BACnet server. The S4 Open: BAC...

The Tracer Communications Bridge - N2 is available for order directly through Trane channels.

The N2 Bridge is the Trane brand labeled version of the S4 Open: BACnet-N2 Router. It has all the same capabilities, plus it contains Trane customized device type templates that allow you to use standard Trane graphics if you are in the SC or ES environment.

Procedure
Tracer Communications Bridge – N2 to BACnet/IP support page: http://www.trane.com/COMMERCIAL/Internal/View.aspx?i=2809

This item is currently in limited release, and all opportunities are being coordinated through Chuck Lehn clehn@trane.com (651) 407-4208. Approval is required in order to complete the ordering process and release goods for shipment.

Additional Comments
The support page link is to an internal Trane page, access is only available to Trane employees and authorized dealers.
Pre-sales engineering, planning support, and first level technical support are provided by Trane through standard product sa...

In the rare case that a BACnet client has problems communicating successfully with the S4 Open: BACnet N2 Router we provide the capability to turn off segmentation support as a diagnostic tool and as an attempt to give the integrator a less efficient, but still effective, way to continue operations at a site.

Procedure
1. Launch the S4 Open: Management Console.
2. Expand the Network Connections group under the BACnet-N2 Router to configure.
3. Right-click on 'Ethernet' and select 'Properties.'
4. Click on 'Advanced Communication Settings'
5. Uncheck the 'Segmentation Enabled' box and click OK.
6. Click OK on the 'Ethernet Properties' dialog.

Additional Comments
• After the segmentation setting is changed, it may be necessary to restart any running BACnet clients before the setting takes effect and communication returns to normal.
• For more information visit http://www.thes4group.com

This is the inverse of what our products do today. The S4 Open Appliances integrate into a N2 bus and publish what they find to open OPC or BACnet environments.
The icing on the cake is that because of the architecture of the S4 Open appliances, we will not only publish these devices to N2, but to any and all upstream interfaces that are supported by the system.

Additional Comments
In a future series of enhancements we will provide the ability to connect BACnet IP, BACnet MSTP, OPC, SNMP, Modbus, or EnOcean Wireless devices to a N2 bus. These devices will look like a Vendor, VND, device to Metasys and we will provide .PRN files to aid in bringing the point list into Metasys.

All of our software is written in “C” code with the intent of keeping the code as portable as possible. The OS is Microsoft’s CE 5.0 which gives us near real time performance and an additional layer of insulation from the actual hardware. We’ve stuck with one hardware platform and OS to minimize support requirements but, if the right business case were made, we could port the software to other environments.

When we initially prototyped the system it was on a Windows PC platform running as a standard Windows application. There were a couple of issues that led us to the Network Appliance delivery model.
- Timing on the N2 bus is extremely sensitive
- Error handling on the N2 bus
- Support for our Upstream N2 bus (or Virtual N2 bus) required us to handle the routing and transport of N2 transactions and responses at near wire speed and in a deterministic manner. The
existence of our S4 Open Appliances in a Metasys system is completely transparen...

We have established a test bed that can be utilized to perform interoperability testing with any BACnet or OPC client, device, or application. We establish a virtual machine environment for each manufacturer environment. Depending on the requirements this is either Microsoft Virtual PC or VMware. Initially, this is utilized for establishing compatibility between S4 products and any other manufacturer product. Longer term, this same environment is utilized for customer demonstrations and ongoing support of customer installations.

Please contact us to schedule a test session if you are a manufacturer and would like to schedule a test session, or you are a end user or integrator and have recommendations for product testing.

Additional Comments
One of the reasons that we went to these lengths is that we understand that very few organizations have a complete BAS test environment. Our test bed can be made available through remote access technology for support of mutual customers a...

We focus on what we do best and enlist others to supplement our own skills:
• We have a strategic partnership with Obermeier Software of Verl, Germany for software development and hardware / software integration.
• We have carefully architected the products so that each feature that we develop is reusable in a Lego-like manner. This maximizes our ability to make each product enhancement quickly available
to all members of the S4 Open product family and minimizes our support cost because the code base for each feature is only maintained in one place.
• We made the strategic decision early on not to be in the hardware design and development business. All of our products are hosted on commercially available, highly reliable industrial PCs.
• We also made the decision that our products would be delivered as network appliances. That is, a fully integrated bundle that includes hardware, pre-installed software, and wizards to aid the
installer with system setup a...

We are a small business and will be adding staff in multiple disciplines as sales of our initial products ramp up.

The S4 Group, Inc. is an S-Corp incorporated in the State of Utah, USA.

The S4 Group is a software and network appliance developer that specializes in products and associated services for two markets.
1. The S4 Open product line addresses Building Automation integration to open environments.
2. The Obermeier Software SNMP OPC Gateway products address integration of Industrial Automation and Process Control (generically non-IT) systems to, and from, enterprise environments.

Steve Jones is managing partner (more formally owner and president) of the corporation. Steve’s bio can be found in the About Us area of the site.

All of our software is written in “C” code with the intent of keeping the code a portable as possible. The OS is Microsoft’s CE 5.0 which gives us near real time performance and an additional layer if insulation from the actual hardware. We’ve stuck with one hardware platform and OS to minimize support requirements but, if the right business case were made, we could port the software to other environments.

When we initially prototyped the system it was on a Windows PC platform running as a standard Windows application. There were a couple of issues that led us to the Network Appliance delivery model.

• Timing on the N2 bus is extremely sensitive

• Error handling on the N2 bus

• Support for our Upstream N2 bus (or Virtual N2 bus) required us to handle the routing and transport of N2 transactions and responses at near wire speed and in a deterministic manner. The existence of our S4 Open Appliances in a Metasys system is completely transparent to the upstream supervisory c...

This is the inverse of what our products do today. The S4 Open Appliances integrate into a N2 bus and publish what they find to open OPC or BACnet environments.

In a future series of enhancements we will provide the ability to connect BACnet IP, BACnet MSTP, OPC, SNMP, MODbus, or EnOcean Wireless devices to a N2 bus. These devices will look like a Vendor, VND, device to Metasys and we will provide .PRN files to aid in bringing the point list into Metasys.

The icing on the cake is that because of the architecture of the S4 Open appliances we will not only publish these devices to N2, but to any and all upstream interfaces that are supported by the system.