Micrologix 1400


#1

I have a Micrologix 1400 PLC using Ethernet Ip for communicating to a X-Gateway AB7632.
Can I target a specific memory location in the Gateway to write data too with a message instruction in the AB PLC? I have 2 plcs writing to the same gateway so i need to write to specific locations within the Gateway in order to not create conflict in the program.


#2

Hi,

You could use modbus TCP to able to make single writes or multi writes to the appropriate memory addresses. This will only write to those addresses. See the modbus memory maps in chapter 5 of the Ethernet User Guide.

If you are using Ethernet IP I do not think we can be sure data is not over written. You are reading and writing the entire assembly instance so there is no way to specify an offset or not read the entire thing. I would suggest trying to just change one variable and verify it does not over write the other PLC’s data.

Regards,
Deryck


#4

I cannot use Modbus TCP. That’s why I need the gateway. The Micrologix side is ethernet ip. Are you telling me there is no way to target a specific memory location in the Gateway if I use Ethernet Ip to send the information?


#5

I am checking this with my colleagues in Sweden I should have a response Monday or Tuesday.