How does a PLC work with Integris software?

This article will briefly describe how a PLC works with OPI’s Integris software

Although Integris is a software designed to Monitor temperature and Relative Humidity/Moisture content (HR/MC), ambient conditions (temperature, HR and rain/snow) and to control fans/heaters/chillers either manually or automatically based on OPI’s control algorithms, sometimes because of a customer’s requirements or a special application a PLC is put into the equation. In this case, Integris has been designed to communicate with a PLC via a third-party application: Kepware, which, by the way, requires a license to be purchased.

Through Kepware, Integris can pass all this information (analog and digital inputs and outputs values) on to a PLC. For this purpose, the PLC should be able to communicate with Integris using a communications protocol known as MODBUS.

Kepware software should be installed on the same PC/machine Integris is installed. It will act as a communications bridge between Integris and a PLC. How does this work? The following lines will explain how this works.

 

  1. Integris is provided with a feature/functionality (OPC) that publishes tags. These tags are memory registers that contain digital information (digital inputs/outputs) gathered by Integris like:
    1. Temperature readings from temperature sensors - Inputs
    2. Relative Humidity readings from moisture sensors - Inputs
    3. Pressure readings from the Plenum Pressure sensors - Inputs
    4. Rain/snow detection readings (on/off) - Inputs
    5. Fan(s) ON/OFF – Outputs
    6. Heater(s) ON/OFF – Outputs
    7. Chiller(s) ON/OFF - Outputs
  2. All the previous information is presented/published (in real time) on memory registers called tags. These registers/Tags are accessible for a PLC via Kepware software, and OPC functionality should be enabled within Integris software to allow this communication between Integris and Kepware.
  3. Kepware read those registers/tags and pass this information to a PLC via MODBUS communications protocol, so a PLC can either:
    1. Based on the information received from Integris, execute a customized control action to operate fans, heaters, chillers, or any other control device
    2. Operate fans, heaters, chillers, or any other control device, based on the Integris control algorithms and control signals (Outputs)