I'm helping my father's job

[mellonge]

hello i'm not good at english, please understand
i just found this website from googling, while i was looking for how to use program(from m340) in m580 environmemt (both from Schneider)
my father said, m340 environment's start address with 1 since it's old version,
and m580's start with 0.
My dad is now trying to use the program he was using at m340 at m580, but he said that since the address value of the existing program starts with 1, the address value should be -1 to use it at m580.
Schneider told me to use system word %SW138 and %SW141, but I don't know how to use it.
I just added %SW138 and %SW141 in the data editor and nothing changed.
Is there anyone know how to offset the address that the program uses by -1

 

[Corsair]

This is a result of the Modbus offset issues that have plagued the protocol for years - and it is fuel for the fires of the Modbus haters on this website.

The first issue is address alignment requirements for values like REALs that use more than one register. The older Quantum processors let you put a REAL at %MW23 or %MW24. Since it is 32-bit data in each case it would use 2 registers. If you started it at %MW23 it would use %MW23 and %MW24. The newer ARM-based processors like the M340 and M580 make you put it at an even numbered %MW address. I had some large Quantum programs where I chose to start most REALs at odd number addresses. It took a lot of work to adjust things. I think Momentum worked like Quantum.
This should not be a problem in an M340 to M580 translation since they both use the newer CPUs.

Your issues are more likely with the HMI or with communications to other devices - but I'm not sure there is an M340 to M580 difference here. There definitely was with a Quantum to newer CPU change. It has to do with how a register called '400100' in an old-style interface mapped to the processor. In some CPUS it was %MW99, in some it was %MW100. Most HMI software (including ours) had a way to adjust the HMI read and write commands so that '400100' goes to %MW100.

Modicon (Schneider) provided the system registers for a way to keep peoples HMIs working. If it can be adjusted at the HMI the system registers can be left at their default values. This is the action that I would recommend. We tell people to not use %MW0 for HMI data.

I'm not sure what your problem is. It may be that you do not have a problem since this is an M340 to M580 conversion. Do you think you need to adjust variable addresses? The people at Schneider may be giving you a standard answer since they aren't clear about your concern. With more information we may be able to help.

Welcome to the forum.

 

[mellonge]

there's no problem in working system, but the problem occured on the display(gp-pro)
He wanted to be displayed as before, but the address value was added 1 and the data value was pushed back one by one.

 

[padees]

Modbus can be an issue. It depends on the developer program of what they are thinking writing their protocol.

Generally it is usually 0 or +1 for address.

If that fails, pick it apart, and re-assemble it into something meaningful and reliable.

 

[Corsair]

I'm assuming that you have no peer communications to other PLCs. The HMI is all that we are worried about.

Go into the program and put in a couple of MOVE blocks. One to each of the %SW system words. On the left side of the block try 0, +1, and -1 and see what happens on the HMI. You may have to cycle power after making each program change. I've never used them since we always adjust on the HMI end.