Popefester
Member
- Join Date
- Feb 2004
- Posts
- 4
Hi all,
This is a fairly quick question I’m hoping a guru can help me out with.
I have a client who needs a communications protocol developed to interface an SLC 5/05 to a proprietary device over a RS485 network. They want the BAST module to do a lot of the work involved in writing this protocol.
Now, I’ve used the BAS module before in the past to do some other stuff like this before, trouble is I never wrote the original BAS code. Looking at the BAS manual though it was fairly simple stuff. The original code used Call 22 / 23 and all the work was carried out in the PLC.
I could go along the same lines and looking at it, may have too, the thing is I noted that there are calls 53 / 56 ( or something like those numbers from recollection ) whereby the BAS module and SLC can pass information between the processors via the M registers. This information is stored in the input / output buffers of the BAS module ( word 100 onwards ).
Point 1 : I’m I right to believe that these input / output buffers for the SLC communications are totally separate to the PRT buffers as indicated in the manual. I get the impression they are and it would make sense.
Point 2 : How do I access the buffers ? Can I do it via the DBY instruction and if so what memory location does the input/output buffers start ? Or is there another way to access the input / output buffers ?
Any help / guidance would be appreciated
Cheers
Daz
This is a fairly quick question I’m hoping a guru can help me out with.
I have a client who needs a communications protocol developed to interface an SLC 5/05 to a proprietary device over a RS485 network. They want the BAST module to do a lot of the work involved in writing this protocol.
Now, I’ve used the BAS module before in the past to do some other stuff like this before, trouble is I never wrote the original BAS code. Looking at the BAS manual though it was fairly simple stuff. The original code used Call 22 / 23 and all the work was carried out in the PLC.
I could go along the same lines and looking at it, may have too, the thing is I noted that there are calls 53 / 56 ( or something like those numbers from recollection ) whereby the BAS module and SLC can pass information between the processors via the M registers. This information is stored in the input / output buffers of the BAS module ( word 100 onwards ).
Point 1 : I’m I right to believe that these input / output buffers for the SLC communications are totally separate to the PRT buffers as indicated in the manual. I get the impression they are and it would make sense.
Point 2 : How do I access the buffers ? Can I do it via the DBY instruction and if so what memory location does the input/output buffers start ? Or is there another way to access the input / output buffers ?
Any help / guidance would be appreciated
Cheers
Daz