Synchronous Block transfer with Basic module 1771-db series A


Thread Starter


Hi everybody,

I want to pass data between the PLC5-processor (5/20) and the Basic Module 1771-DB series A using synchronous Block Transfer. I have an attachment file include with the rungs and the basic-program for the Basic-module. The problem is when the basic-program execute Call 6 (row 50) nothings happen, call 6 means that this routine receive data from the plc and the active bit from the Input Image Table
(I:013/1) must be '1'. But I:013/1 is not '1' so the rung for the BTW is not true and nothing happend. When I toggle bit I:013/1, the rung is true and data is being received.
The same is for the BTR. Who can help me what the problem is?



Yosef Feigenbaum

Wow, I'm going to have to dig deep in to my memory on this one.

From what I remember the Call 6 and Call 7 would cause the module to wait for a block transfer. Call 2 and Call 3 wouldn't. If you don't want the module to hang up the you can loop on the Call 2 or Call 3, periodically leaving the loop to check on other things you may need done.

Good Luck,

(8{)} ( .)
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