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rayen_6827 · Member junior Joined: 21 Jun 2013 Posts: 67

hello

in my project s7-417(step7)

There are a number of four-wire and two-wire Which contains “FIT TT PIT “are Sometime in monitoring displays the amount of overflow(7FFF).

And when we disconnect one of the THEY from the terminal of the input module, their values are displayed

The AI module is not fault as i checked it on the CPU ,project it is working fine.

For example, in a module analog some of the channels two-wire and some four-wire configuration have been

For example, overflow that happens if we open wire negative an consumption transmitter of channel the other channels to the amount of normal returns and are OK
the order code modules are :331-7kf02-0ab0

Can I be in a module with8 INPUTs:

I configured this way: connected4 SENSORto the module 4-wire current transducer

AND2 SENSORCONECTED to this module 2-wire current transducer

Is there a problem with this configuration, which is used in combination.

for example:CH0 ,CH1\CH2,CH3 is 2DMU

AND CH4,CH5\CH6,CH7 is 4DMU

I think that's the problem
Because their winring is different from that of Siemens method

wiring: Sometime Analog module showing overflow value 7FFF Sometime Analog module showing overflow value 7FFF

Sometime Analog module showing overflow value 7FFF Sometime Analog module showing overflow value 7FFF

bakki · Junior Joined: 30 Nov 2017 Posts: 10

For sensing wrong values to AI you can use an appropriate program.
http://plc.myforum.ro/analog-scaling-blocks-vt8385.html
For connecting two wires and four wires transducers at the same card all you need is to do it correctly to the pending AI channel.
Sometime Analog module showing overflow value 7FFF Sometime Analog module showing overflow value 7FFF

The AI do not "know" if there are 2 or 4 wires if it is correctly wired.

The 4 wires connection is usually used in case you are using Sensors with Variable Resistance for taking into account the wires Resistance.
If you do not care about wires Resistance the connections P++ and M-- must be linked together for 2 Wires transducers.