Q Series analogue input - change to passive

[Tjkeets90]

Hi,

I have a device which is giving out a 4 -20mA signal but the ADC's on the PLC channel do not match.

The supplier is saying the channel needs to be active and not passive.

I am using GXWorks2 and have looked through all the settings but can not find any reference to passive or active.

Has anybody changed this before?

 

[goghie]

I presume that it is about wiring, not about software configuration. Do you have 2-wire sensor?

 

[parky]

It depends on the Analogue card, some have power (24V) some do not.
Generally for a passive sensor (2 wire) then you put +24v onto the + of the sensor, the -ve of the sensor then goes to V+ & I+ on the card, the V- on the card goes back to the 24v supply 0V or -ve,
So in actual fact, the sensor then becomes active.
If it is a 3 or 4 wire sensor then the power is fed to the + & - of the sensor the out & - of the sensor (two wires) is fed to V+ & I+ (together) & the - is connected to the V-