I need a way of going from the master, to an mMINT module (INCOM to modbus) then from Modbus to TWO redundant modbus/tcp ethernet cables. This is for the event that one of the cables breaks.

I was looking at Arbiters, but they seem to perform arbitration for a master and not the slave....

Is what i'm doing possible. ?????

 

If your software is smart enough to support 2 IP for the 2 slaves and switch between them, then you have no problem.

But since you ask, I assume your equipment (the mMINT module) is NOT smart enough to support backup IP. Adding a arbiter kind of defeats the purpose - adding yet another single-point of failure is rarely the answer. Can you define this better? Do you want 2 remote IP supported or
the same IP for 2 devices?

You need to either find a way for the mMINT module to support 2 IP for the remote, or find 2 MB/TCP slaves that can cooperate and share a single IP. But even this is not trouble-free because of the issues of ARP cache mean the idea of an IP moving from 1 MAC to another MAC can take up to 5 minutes to be accepted by common TCP/IP devices that are NOT designed to understand such movement.

best regards
- LynnL

 

Hi

Sixnet has device called ET-GT-ST-3 where is two ethernet networks, 1 rs232 and st-bus. You could configure rs232 port to Modbus master and passthru that to ethernet ports.
Here is link. http://www.sixnetio.com/html_files/products_and_groups/etgtst3.htm

Tommi Vahtera
THT Control Oy
www.thtcontrol.com
[email protected]