A
DEAR ALL
I would like to know whether the following thing is possible or not.
Let us take a simple case. I have a PLC and DCS. And my PLC wants to communicate with DCS through hardwired communication.
For example, one pressure transmitter is there in the field. The signal is going directly to PLC as analog input(4 - 20 MADC, 24 DC). The transmitter is powered by PLC (24 VDC power supply). The same pressure transmitter signal is required in DCS also. The PLC gives analog output of the pressure transmitter signal which will be taken into DCS as analog input(4-20 MADC, 24 VDC).
My question is when PLC gives as an analog output 4-20MA DC, 24 V DC, whether DCS can power the loop and take the signal as analog input and at the same time PLC will not loop the power. In otherwords, whether it is possible to have analog output from PLC without powering the loop and DCS powers the loop(PLC-DCS loop and not field-PLC /DCS loop). This is similar, not exactly, I.E., potential free contact output in the case of digital output.
In short, instead of source device (PLC) powering the output loop (4-20MA DC,24 VDC) the destination device (DCS) powers the loop and takes the signal as analog input (4-20MA DC,24 V DC).
Thanks
Anand S
I would like to know whether the following thing is possible or not.
Let us take a simple case. I have a PLC and DCS. And my PLC wants to communicate with DCS through hardwired communication.
For example, one pressure transmitter is there in the field. The signal is going directly to PLC as analog input(4 - 20 MADC, 24 DC). The transmitter is powered by PLC (24 VDC power supply). The same pressure transmitter signal is required in DCS also. The PLC gives analog output of the pressure transmitter signal which will be taken into DCS as analog input(4-20 MADC, 24 VDC).
My question is when PLC gives as an analog output 4-20MA DC, 24 V DC, whether DCS can power the loop and take the signal as analog input and at the same time PLC will not loop the power. In otherwords, whether it is possible to have analog output from PLC without powering the loop and DCS powers the loop(PLC-DCS loop and not field-PLC /DCS loop). This is similar, not exactly, I.E., potential free contact output in the case of digital output.
In short, instead of source device (PLC) powering the output loop (4-20MA DC,24 VDC) the destination device (DCS) powers the loop and takes the signal as analog input (4-20MA DC,24 V DC).
Thanks
Anand S