Gas detector Wiring

Hey everyone!

I have to install 4 new gas detectors (MSA x cell sensor) those are three wire devices (24+,24-,Signal)and to be added directly to DCS without a gas detector panel.

DCS is of yokogawa centum with io card aai135h00.Can I do it directly to DCS by sharing power supply common and signal.
Does this affect 4-20mA signal if we make it common.Also detectors are having a current of 300mA.
Is there any interface terminal board to do this?
The DCS world is closed world, where vendors require vetted registration before allowing access to documentation. As a worker bee, I am not a DCS owner/operator and hence I have no access to Yokogawa DCS documentation. Without knowing the details of that analog input card it's speculation on my part as to what its functionality is.'

Many DCS AI cards expect to be connected to a 2-wire, loop powered field transmitter and therefore supply the DC voltage necessary to operate the loop right on the AI terminals. This is called an 'active' input, where the loop power is supplied directly on the AI terminals and the active input connects to a passive (2-wire, loop powered) field device.

Sometimes AI cards can be configured through some means to disable the DC power supply for a 2-wire loop powered field instrument and operate as passive input. Sometimes not.

If that card is designed so that it always supplies loop power, then you can not connect and get it to work because the field instrument is an active, 3-wire output, which is incompatible with an active, (3-wire) analog input.

If the card is designed so that the loop power can be disabled from the input terminals and the card can act as a passive input, just monitoring the current signal and NOT providing loop power, then it is likely that you can connect a 3-wire field instrument using a separate DC power supply (make sure you fuse the power supply connection to the instrument) and jumpering the DC common/(-) to the AI (-).

The issue might be any ground potential difference between the DC power supply (-) and AI (-), because those points will have to be connected for a 3-wire circuit to operate. Any difference in ground potential will generate a ground current, commonly called ground loop, which could end up causing a shift in the reported signal.