Hello,
I have a couple questions, but first some background:
I have inherited a system that was designed using 2x RMC200-02173.
Each RMC will control the position of around 30 cylinders with independent linear feedback. Both RMCs currently have identical programs, other than the IP addresses. The way things work is that the PLC sends a position command to both controllers and both controllers use a move absolute to move a virtual axis to the commanded position, and the real axis use gear absolute commands to follow the virtual axis. I don’t really want to change any core logic as it is a double up of a previous system that worked very well.
But there is some concern both from myself and the end customer that doing this might introduce some small difference in position between the two RMCs’ virtual axis positions at any point in the move. I assume they will be close, but not perfect. And I am guessing it is impossible to say how large this error would actually be without testing it.
Okay, now on to my actual questions:
- Is there a way to have 2 RMCs communicate with each other over Modbus/TCP in order to synchronize the virtual axis position?
- I see from the manual register synchronization can be done with a UI/O module on the RMC150, would this also work with the U14 module for the RMC200? On the website, it does not expressly say it can output SSI from a register like the UI/O module does.
I was also considering the idea of having the PLC relay the position of the virtual axis from one controller to the other if they cannot communicate directly, but I am not sure if this would really be much more accurate overall as that will introduce some delay.
Any help is appreciated! Thank you.