Regarding instrument communication issues
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I have 8 ultrasonic flowmeters that use 485 communication. The flow rate values are displayed on the meter located at the physical end of the cable, but no corresponding values appear on the remote PLC. When I changed the address code of this meter to that of another working meter, the values appeared on the PLC. Is this a problem with the meters? I appreciate your guidance.
This post was last edited by ssln123 on 2022-4-23 08:35. If the communication settings for this flow meter are not displayed and appear to be correct, then it can be concluded that there is a problem with the communication functionality of this flow meter. I have actually encountered such a situation where the flow meter was working properly, but there were issues with the output current and communication.
First, ensure that there are no issues with the wiring and that the communication ports are connected properly. Modify the addresses on the instrument side and the PLC communication side so that they match, then check whether it’s possible to read the values. Note: Can’t there be duplicate addresses for the same 485 communication? It will cause problems
1. Check whether there are any duplicate address codes. 2. Check whether the communication cable is broken somewhere along its length. 3. It is possible to check whether there is a communication fault with the flow meter using the host computer software (PLC/DCS). 4. Whether there is interference in the RS485 level RTU circuit, and the length of the communication cable, etc.
Yes. Instrument engineers can do anything. Communication is one aspect. It’s broken; it’s a problem with the gauge.