Modbus TCP and Campbell Scientific CR-6 Communications Problem

T

Thread Starter

Tim

ModBus/TCP is hanging up... connectivity: Linux RedHat 6 -> 10/100 workgroup data switch -> Campbell Scientific CR-6 (ModBusSlave, port 502)

There is a host server plugged into the switch also... it is not supposed to be actively involved in the ModBus transaction... however, when disconnected, ModBus hangs... Linux has static IP as does the CR-6... tried DataGram w/ TCPOpen, no joy... ping works always... ModBus usually restarts in <60s after the host server is reconnected, with no error reported... once, got a 'broken pipe' error... any clues available?
 
Hi Tim,

>ModBus/TCP is hanging up... connectivity: Linux RedHat 6 ->
>10/100 workgroup data switch -> Campbell Scientific CR-6
>(ModBusSlave, port 502)

I have 15 years experience with Campbell Scientific dataloggers, but never used the CR-6 specifically.

I recently added Modbus/TCP to my simple example here:
http://ctrlterm.com/custom.htm

If you would like to use that example for testing, please contact me by email. Hopefully someone here will have some suggestions to easily solve your problem.

Regards,
Paul
 
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