Metasys N2 to BACnet MSTP Gateway | |Metasys N2 to BACnet MSTP Protocol Converter
  • This gateway can read Modbus data from your Metasys N2 devices and publish it as BACnet MSTP data.
  • It can also write to the Metasys N2 devices.
  • This gateway can also do the reverse, read BACnet MSTP data and publish it as Metasys N2 data.
  • It can also write to the BACnet MSTP devices.

In summary, this gateway can act as:

  • Master on the Metasys N2 network: Hence it is capable of reading data from the various Modbus slave devices and writing data to them if required.
  • Slave on the Metasys N2 network: You can use the gateway in this mode if you have a Metasys N2 master on the network which would be reading data from the gateway.
  • Master on the BACnet MSTP network: Hence it is capable of reading data from the various BACnet MSTP devices and writing data to them if required.
  • Slave on the BACnet MSTP network: The gateway can be configured to be a server of data values; hence another BACnet MSTP client can read data from the gateway and write data into the gateway.

Block Diagram:



Application Scenario 1
  • On a site you have several Metasys N2 controllers that can provide data output on Metasys N2.
  • The site has a SCADA on BACnet MSTP that needs the data from the Metasys N2 controllers.
  • Since the Metasys N2 controllers provide data output on Metasys N2 and the SCADA understands only BACnet MSTP a direct data exchange is not possible.

Block Diagram:


Solution:

The devices can not directly communicate with each other as they are not on the same protocol. Metasys N2 and BACnet MSTP are Serial based Protocol. You need something that will convert data from BACnet MSTP device to Metasys N2 and vice versa.

ProtoConvert’s Metasys N2 to BACnet MSTP converter will be an excellent solution for this requirement. The gateway reads data from the Energy meters on Metasys N2. It caches this data internally and then provides it on BACnet MSTP when requested from the SCADA system.

Application Scenario 2
  • On a site you have several variable frequency drives that can provide data output on BACnet MSTP.
  • The site has a NAE controller on Metasys N2 that needs data from Variable Frequency drives on BACnet MSTP.
  • Since the Variable frequency drives provide data output on BACnet MSTP and the NAE controller understands only Metasys N2 a direct data exchange is not possible.


Solution:

The devices can not directly communicate with each other as they are not on the same protocol. Metasys N2 and BACnet MSTP are Serial based Protocol. You need something that will convert data from BACnet MSTP device to Metasys N2 and vice versa.

ProtoConvert’s BACnet MSTP to Metasys N2 converter will be an excellent solution for this requirement. The gateway reads data from the Variable frequency drive on BACnet MSTP. It caches this data internally and then provides it on Metasys N2 when requested from the NAE controller.


An Overview of the two protocols

Metasys N2:

Metasys N2 was developed by Johnson Controls as a network to interface their various devices and controllers. It is on the physical layer RS-485 set of data communications standards and supports 9600 baud, 8 data bits, and no parity and in half-duplex mode only. This network supports communications with a huge range of devices manufactured by Johnson Controls and some other companies. Metasys N2 by Johnson Controls is a master/slave protocol with one master only so it is not possible to have two devices performing this function on the same network.

BACnet

BACnet (Building Automation and Control Network) is a communications protocol that helps the communication between building automation end-devices and building management systems. The BACnet protocol specification like every other protocol specification defines both how data is represented on the network and the services that are used to move data from one BACnet node to another. The specification also tells us about messages that identify data and network nodes such as who-Has, I-Have, Who-Is, and I-Am.
To meet the requirement of the widest possible set of applications BACnet was designed to support several different physical and link layers.

BACnet MS/TP (master slave/token passing)

MS/TP is exclusive to BACnet and can be implemented using the EIA-485 signalling standard. This is a shielded twisted-pair (STP) LAN operating at speeds from 9.6Kbit/s to 76.0Kbit/s. This LAN type is particularly suitable for single controller and