Connecting self-powered analog signal to Moore PLC


Thread Starter

P.V. Shyam

We are using Moore APACS/Quadlog PLC. The analog cards are Moore SAM (Standard Analog Module). The SAM accepts 4-20 mA DC two-wire transmitter signals and provides the 24 V DC loop power. The inputs need to be sinking type.

I have one input from an analyser which is 4-20 mA DC signal which does not need loop power because it derives its power from the analyser and is non-isolated. I want to connect this to the SAM module and achieve signal isolation for input to the SAM at the same time. Does anyone know of the solution, a suitable interface card (for example, from the range of Pepperl & Fuchs?).
We have the APACS at my plant. You will not be able to connect the analyzer to an SAM card. You need to connect to an EAM card. If you have a spare point on an existing EAM use it. If no spare you will have to buy new card for Rack and termination card with interconnect cable. This will run you about 4 grand.

Hope this helps.
Thanks. The isolator would have to be powered by the loop power from the SAM card because this Moore card supplies loop power for the 4-20 mA loop. Can't turn it off to accept self-powered loops I believe. If you know of Pepperl & Fuchs or similar vendor's model do let me know.
I'm sure you've solved your problem by now but, Moore Industries offers an isolator for ~ $350. The model number is SIX/4-20MA/4-20MA/12-42DC/RF[DIN]

This allows the 24 VDC from the SAM card to supply power to the output side of the isolator. The input side accepts the isolated 4-20 input from the field device.