RTU(TCP) or DCS (customer side ) display signal is fluctuate

It is PLC input need to add resistor ? on panel meter is requested add 250ohm, we already add.As per our supplier mention PLC  siemens 6ES7231-4HD32-0XB0 is can't connect on series, if we need to connect panel meter and PLC for both , need to add splitter 4-20mA?

or because series connection be come signal fluctuate

Closed cause question posted twice.

The second thread with the subject 4-20 mA signal is fluctuate is published within the conference SIMATIC S7-1200.