0

I have a PLC that already have a big map (3000 registers). I have a PC software to talk to the PLC.

Now the customer want to re-arrange the registers. I wonder whether I can map the same logic to a second map. example, to my software, Modbus ID 1: 40001 is to move a valve, and customer want to move to 40100. so is there a way to do the same thing to both ID 1:40001, and ID2:40100?

This is a general question. if you need to know my PLC underlining programming language, I have to take a look.

Splash
  • 1,288
  • 2
  • 18
  • 36
  • The 3000 registers are all holding registers? – Ronaldo May 30 '16 at 10:28
  • most are holding registers. Some holding registers are going to be input registers now since they are read only. – Splash Jun 03 '16 at 21:38
  • Your customer wants to move to 40100 or can it be another range? You can have 65536 holding registers in your PLC, so there's a lot of room for moving registers around without requiring another ID. – Ronaldo Jun 06 '16 at 10:32

1 Answers1

1

This should not be a problem at all. You need to provide more information though if you want how this is to be done.

The problem is actually if for example you need to move 40001 to 40100 and 40100 to 40200, then you need to be sure that the 40100 was moved to 40200 before you overwrite it, as I understand, this is not an issue for you, you are moving to an entire new area. If so, then you are good to go, provide PLC type, software and version, etc. to get a precise answer

Makab
  • 42
  • 4
  • I was thinking to respond to ID 1 with original map, but respond to a different Modbus address say ID 3 with new map. In this way, there is no moving. I would like the PLC firmware to react to either (ID, register) pair, or provide information to be read to both (ID, register) pair if that is possible. – Splash Jun 14 '16 at 16:46