modbus setting in ABB AC500 PM573-ETH
I am using an AC500 PM573-ETH CPU. I am having some basic doubts related to Modbus TCP/IP Server setting in CPU.
1. What should I insert in "server connection"?
2. In Modbus Server Settings, What should I insert in "Disable write/read to %MB0.x From/to"?
Also, while checking it on Modpoll I am continuously getting Read/Write error.
Please, someone, suggest me the solution or some sample code for configuring Modbus TCP/IP server.
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It depends on the version of the AB that you are using.
Look in the Online help for description of usage - everything necessary is described there:
First you have to set the IP address of your port. Then try to ping it from your PC
Server connection means your PLC will be the slave.
From the help:
1. Server connections = Maximum number of logical server connections allowed in parallel. 0 means only Client usage (Modbus Master). Requests from other Clients are ignored
So if you want your PLC to be slave and respond to your master's requests, put some value here, e.g. 1 for one master request (different from 0 for slave functionality)
2. Disable write/read to %MB0.x From/to
Normally you don't have to define anything here, if you want to access the full range of your mapping from outside.
If you want to make some area of your mapping invisible from outside, then you have to do it here