Dear all,

We are planning to install several new equipments, having more than 300 instruments (temperature, flow, pressure, etc) in our power plant. Current process control is through a DCS and we are planning to use the same for controlling new equipments.

Other existing instruments are wired individually to DCS. But we need to wire new instruments through single communication link (2 wire, 4 wire, ?? wire as necessary) that we have not yet decided (but we don’t need to wire all of them individually). I searched the web and found several options like MODBUS/TCP, Fieldbus HSE, I2C, etc.

Distance between DCS (ABB Infi-90) and equipment location is around 600 m.

I’m new to this field and I appreciate any help selecting suitable method for setting up this communication.

Best Regards,
Madu.

 

Dear Madu,

Temperature, flow, and pressure etc. transmitters do not use Modbus/TCP, HSE, or I2C. FOUNDATION fieldbus H1 is the way to go. However, you cannot connect all 300 devices on the same pair of wires. You will be limited to about 10 per bus. So you would need about 30 such 2-wire buses. These 30 buses can in turn connect to an existing DCS like infi-90 through linking devices / gateways to Modbus/RTU or Modbus/TCP.

Cheers,
Jonas