Popular PLCs Support BACnet/IP Automation Protocol

IDEC has added support for the BACnet/IP building automation protocol to its family of MicroSmart FC6A Plus PLCs. BACnet stands for Building Automation and Control Networking Protocol, reportedly the leading global protocol for networking HVAC, lighting, security and other systems commonly found in commercial and industrial buildings. This open protocol has been standardized under the ANSI/ASHRAE 135-2012 specification for interoperability among systems built by different manufacturers.

 

Built-in support for the latest version of BACnet, BACnet/IP and its B-ASC profile allows equipment and systems using the company’s PLCs to act as a BACnet Server and connect via the PLC’s Ethernet Port 1 to other building automation BACnet Client controllers and systems for data sharing, trending, scheduling, alarm and event management, device and network management, and other functions. Supported PLC object types analog input, analog output, analog value, binary input, binary output, binary value and device. Up to 256 objects can be simultaneously supported, with up to 64 bytes of characters for each.

 

Support is provided for Subscribed COV (change of value), Unsubscribed COV and Foreign Device functions. With the Subscribed COV function, the BACnet Client sends a subscribe request, and the BACnet Server, such as an IDEC MicroSmart FC6A Plus PLC, sends “Present Value” and “Status Flags” when these parameters change.

  • The Unsubscribed (or Unsolicited) COV function is similar, but in this case the BACnet Client does not need to send a subscribe request to the BACnet Server because it sends the designated data to the Client whenever the data it changes.
  • The Foreign Device function permits an external BACnet device to be linked to a BACnet/IP Broadcast Management Device (BBMD). If the device is registered to the BBMD, the device can communicate to other devices linked to the BBMD

 

Configuration for BACnet communications is done with drop-down menus by clicking on the “BACnet/IP Settings” tab and following the on-screen instructions. For more details, visit IDEC and call 800-262-4332.