AB RSView to PLC-5 Addressing


Thread Starter

Brendan Kirby


I'm trying to request data from a PLC-5 look-a-like from RSView. My look-alike which is talking Full duplex DF1 can only handle a read of 8 floating point parameters at a time. If i attempt to read 2 parameters that are spaced some distance apart in memory then RSLinx/RSView does a request for the whole block of memory in between. I can't seem to limit the size of the requests. Anyone hit on this yet? By the way i am using the NET-ENI module to convert the Ethernet out of the computer to the DF1.

Thanks in advance,

Brendan Kirby

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Blocking the requests is pretty common for communication drivers like RSLinx. This is done A) to reduce overhead and B) because it needs both data points in one request.

The best way to take care of this is to re-arrange the addresses inyour PLC. Just do some MOV blocks to take your data that is spread about, and put them into a contiguous section of memory. Then you can pluck them out 7 at a time, and not be wasting any bandwidth moving unwnated data.

The other option is to request the data points one at a time.


--Joe Jansen