Multiranger 100/200, 4-wire mode problem

I know this is an old post but I have a similar question to the subject here.

We have a Siemens Multiranger 100/200 device that has the 4-20mA output connected to the AI input of a Siemens S7 PLC. However, when the analog input is set up for 4 wire mode it does not register the signal, when the PLC gets connected the mA and voltage signal drop down. However the cards and backplane etc are not in fault because we have injected into the PLC and it registers the signal fine (when having the 4-20mA signal supplied with voltage from the injector). Then, when the input channel is set-up for 2-wire mode, the signal works perfectly fine and registers the correct signal.

The multitronics appears to have the voltage (24V) on the line with the 4-20mA at all times, looking through the Siemens S7 manual, it shows the only real difference between the 2-wire mode and 4-wire mode as being the resistors, but there is more resistance on the 2-wire.

How is the Multitronics working only on 2-wire mode, when I thought it's output was active and powered by the Miltronics itself, not loop powered from the PLC?

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Split from I have problems with Miltronics Multiranger 100/200.

Closed cause question published twice.

The second thread with the subject Multitronics 100/200 connected to S7 PLC, working only on 2-wire mode? is located within the conference Process Instrumentation / Analytics / Weighing Systems SIWAREX.

Best regards
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