modbus tcp error

[benanderson_475]

HI, 

Im getting two errors on a from Modbus profile i altered/made for solar inverter, how can i work out which register is causing the error?
or is it by process of elimination?

These are the errors
Solar Inverter (TCP 192.168.1.120:502) read failed: Invalid data
Solar Inverter (TCP 192.168.1.120:502) read failed: Operation timed out
Solar Inverter (TCP 192.168.1.120:502) read failed: Invalid data

how can i know which register/s in the profile are causing the error/s?
it seems like it runs good for a time then error happens, then goes ok for a time then error again so it seems intermittent.

Maybe i have something incorrect in the profile? or maybe its a TCP issue?
Any ideas?

[admin]

Invalid data means that the read request was not fully sent or the reply is incorrect. Most likely the profile is not at fault here, it's an issue on the inverter.

You can try enabling or disabling persistent connection mode and see if it makes a difference.

[benanderson_475]

Thanks for this, ill look into the inverter end...
What about 

read failed: Operation timed out  - i have another modbus RTU device that sometimes flags this error as well

What is the likely cause of this error polling too fast ?? change poll interval? or something else?

Many Thanks

[admin]

In rare cases RTU devices require an additional delay between each request. It can be enabled by setting read_delay field in the profile. Also communication can be improved by connecting GND between RTU devices if you haven't done so already.

[benanderson_475]

In rare cases RTU devices require an additional delay between each request. It can be enabled by setting read_delay field in the profile. Also communication can be improved by connecting GND between RTU devices if you haven't done so already.

Many thanks, 
The read_delay fixed it for me