What can be the reasons my PLC is not receiving data from modbus slave with baud rate 9600.Data is being scanned in modbus scanner but even through all parameters from both sides are same, data is not being displayed in Ecockpit.
Without more information, as a rule of thumb:
Check the cabling, haven’t you inversed the A and B line (it happen a lot …)
Check the communication parameters (stop bit, data size, parity, etc)
Check the modbus ID (is the addressing correct ?)
Do you have any information on the slave to show it is receiving a request ?
Any information about the slave sending an answer ?
What slave is it ?
Are you sure the function code and the memory address / data size is supported by the slave ?
If any of above would have caused this issue, it should have been same for 19200 baud rate, but it reads all data with that baud rate.
Slaves are two energy analyzers and two huawei solar inverters connected in daisy chain. When I set baud rate of all the devices 9600, the data of energy meters is being scanned but not showing on ecockpit.
If it works at 19200 baud, but not 9600, perhaps the inverters are not actually changing to the 9600 baud setting? Perhaps they need to be power cycled for the new baud rate to be applied, etc?