I have RTS terminal server (Modbus switch). Values from RTU drops to zero. Is there modbus versions that could not be communicating properly with our RTS terminal server? Or it's only one Modbus version.
If there's no reply 2 weeks then others are as confused with the lack of specifics as I am.
1. What brand model terminal server/MODBUS switch are you using? Can you provide a link to the spec/manual? I'm not sure what kind of functionality it is supposed to be providing.
2. For serial/Ethernet gateway/converters, models with specific firmware for MODBUS RTU are used because of MODBUS RTU's timing and message integrity requirements. Is your device MODBUS RTU specific?
3. Has this equipement worked before and has now failed or is this task commissioning new devices?
4. When you say 'values from RTU drop to zero' does that mean that the only values received are zeroes, when the known source value is not zero?