Communication between SLC 500 and SLC 500 DH+

I have 2 SLC500/04

The master has it´s own I/O
The slave has it´s owns I/O

if master has an Input on, i want the slave turn on an Output.
how can i tell the slave that the master has an input on and start working from there. i want to control I/O from master to slave.....

Hello,

You will need to use 'MSG' instruction , click on help on the top of your screen and see the MSG help file, also below

See here http://literature.rockwellautomation.com/idc/groups/literature/documents/rm/1747-rm001_-en-p.pdf

Start on page 447

Thanks but i still dont get it, how it´s suppose i´m going to read those I/O what does the MSG send me? where it´s suppose the MSG move those I/O that come from master into the slave?

There is no Master/Slave, this is a Peer to Peer Message (MSG). You specify in your MSG Instruction the Source and Destination, and I would suggest you create an Integer File (N) as the Destination.

Give us some more details, or Post your PLC Programs (Zip it first).

Attached is an example SLC5/04 DH+ Read Instruction.

Stu....

pablorm said:

how it´s suppose i´m going to read those I/O what does the MSG send me? where it´s suppose the MSG move those I/O that come from master into the slave?

Click to expand...

You must map the I/O to suitable Words that can be messaged. I normally set aside at least one 16 bit "N" word for this. Map the inputs you want sent to the bits of this "N" file. by map, I mean: for example: copy the input bit I:01/13 (XIC) to the N7:00/00 bit (OTE).

Then you need to set up the MSG instruction to MSG write to the SLC, give it the source and target addresses, and condition the rung so that the MSG is enabled each time you want this information sent. It has been a long time, but when you choose the channel and then open the dialog there should be a place for the target DH+ address and target device data table address.

You should also trap the error bit.

You can send B3:0 through B3:9 in one PLC to N7:21 through N7:30 in the target in you want...

I strongly suggest that you fully comment those addresses in the target PLC files.

another way to go ...

don't let this confuse you – but since these are both SLC-5/04 systems you can use the Global Data feature to pass just ONE sixteen-bit word between the processors – without using Message commands ...

note that this works only on Data Highway Plus – not Ethernet, etc. ...

if you've never heard of it before, just go to the Global Data tab in the Processor Status file ... then click the Help button and read up ...

the basic idea: on a Data Highway Plus system, each processor takes a turn and transmits its status over the network ... it also sends along ONE "extra" sixteen-bit word which doesn't get used ...

so ... basically you enable the Global Data "mailboxes" and MOV (Move) a sixteen-bit word into a specific location (which matches the processor's own Data Highway node number) ... the processor puts that information out on the network for free ... any other processor which has Global Data enabled can see that word – and take action based on the bit patterns stored there ...

frankly, most people just prefer to use MSG Message commands – but the Global Data feature is available if you want to use it ... just be SURE to document what's going on ... many (most?) technicians have never heard of this – so they'll have ZERO idea of where the data is coming from unless you give them some good comments ... specifically, there won't be ANY logic in the program to make the data move across the network - it's automatically transferred in the background – so it CAN be confusing ...

party on ...

Here is a little more from the manual about what Ron is talking about.

I have used this with a PLC5 and SCL5/04 with great results.

Thank you

Ron Beaufort said:

don't let this confuse you – but since these are both SLC-5/04 systems you can use the Global Data feature to pass just ONE sixteen-bit word between the processors – without using Message commands ...

note that this works only on Data Highway Plus – not Ethernet, etc. ...

if you've never heard of it before, just go to the Global Data tab in the Processor Status file ... then click the Help button and read up ...

the basic idea: on a Data Highway Plus system, each processor takes a turn and transmits its status over the network ... it also sends along ONE "extra" sixteen-bit word which doesn't get used ...

so ... basically you enable the Global Data "mailboxes" and MOV (Move) a sixteen-bit word into a specific location (which matches the processor's own Data Highway node number) ... the processor puts that information out on the network for free ... any other processor which has Global Data enabled can see that word – and take action based on the bit patterns stored there ...

frankly, most people just prefer to use MSG Message commands – but the Global Data feature is available if you want to use it ... just be SURE to document what's going on ... many (most?) technicians have never heard of this – so they'll have ZERO idea of where the data is coming from unless you give them some good comments ... specifically, there won't be ANY logic in the program to make the data move across the network - it's automatically transferred in the background – so it CAN be confusing ...

party on ...

Click to expand...

I was proving what you told me about the global data feature and as you said it´s was pretty simple thaks for helping me all of you, and i hope you have a good day, i was and i´s still happy because of you guys help me instantly