The Siemens PLC cannot read the turbine flow meter
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Hello everyone, we encountered a problem during construction. We tried using 485 serial communication; reading data from other instruments worked fine, and the UT-890 serial communication tool was able to read data from the flow meter, but the PLC couldn’t do so. When the UT-890 was connected to the 485 line and in listening mode, the PLC could read data from the flow meter. However, once the UT-890 was removed, communication stopped, and adding terminal resistors didn’t help either. Is there a problem somewhere?
Serial Port Assistant is capable of sending signals, and then the 485 end sends a response; if no signal is received, it means there’s some issue with the configuration on the PLC side.
We need to assign addresses. Serial Port Assistant has an automatic addressing function, while the PLC requires programming settings