PLC to PLC Communication (Mitsubishi FX2N)

[c0met]

Hello Everyone,

I have a feeling the answer is no, but I would like to verify that.
Here is the situation.

I have one Mitsubishi FX2N PLC set as a Master for the purposes of PLC to PLC Communication in an N:N Network.(RS-485)

I have 5 other PLCs set as slaves for the purposes of PLC to PLC Communication in an N:N Network.(RS-485)

I have no problem getting them to talk to each other.

Ideally I would like to have 2 separate PLC Programs written one for the Master and one for all of the slaves instead of 1 Program for the Master and 5 separate programs for the slaves.

The problem occurs when in the first line of each slave program I have to assign that slave a unique number at position Zero in the ladder logic program.

Ex:

M80038
----- ||--------------------[mov K1 D8176]

This assigns 1 to D8176 telling the PLC it is Slave #1

Changing the value of D8176 later does nothing.

As well moving other D register values to D8176 does not work

Question: Is there a way to dynamically assign a value to this special register?

In English: Can the Slave PLC’s figure out which slave # they are based on terminal input?

I hope that is enough info to go on,

I am happy to elaborate further,

Thanks in advance,

Jamie.

[panic mode]

You mean like "MOV K1X0 D8176"?
(X0, X1, X2 and X3 are address)

[c0met]

I wasn't sure you could do that. I'll give that a shot.

I know that there are V0-V7 and Z0-Z7 index registers that can be used but i had no luck with them

[mov Z0 D8176] Where Z0 was a Slave number.


I also tried

M80038 X1
--||----||---------------[mov K1 D8176]
~~~| X2
~~~ --||---------------[mov K2 D8176]
~~~| X3
~~~ --||---------------[mov K3 D8176]

(Ignore the ~'s)

to no avail.

I'm pretty sure I'm trying to make the PLC's do something they weren't designed to...

Jamie.

[panic mode]

Well if you take a look at this, you will see how to use bit addresses:

--|M8032|----+---|X0|---------------(D8176.0)

             | 

             +---|X1|---------------(D8176.1)

             | 

             +---|X2|---------------(D8176.2)

             | 

             +---|X3|---------------(D8176.3)

You will have to check when is this executed. Most settings are
only accepted at powerup. This means that address setting must
be set (hardwired) before PLC powerup.

[c0met]

--|M8032|----+---|X0|---------------(D8176.1)

Doesn't work.

--|M8032|----+---|X0|---------------(D8176.1)
|
+------------------(D8176.2)

Also gives an error.

I have to agree that it is most likely a hardcoded settings on power up type of thing.

I have to admit defeat!

Thanks for the help,

Jamie.

[panic mode]

Sorry for the M8032, it was a typo of M8038.
You made me look up the manual for D8176 which is reserved
according to JY992D88101A (there might be newer version...).
What do you expect D8176 to be doing?

[Contr_Conn]

Panic: do you need JY992D88101C - over 6MB PDF ?

c0met: are you sure it is D8176? Did you try D8173?