output with readback #21
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Ever since the "bulk read" was introduced, there are 2 ways to handle records with input funcionality (*): - using a notification for this very PLC variable - through a cyclic-poll, where all input-ish variables are read at once, hence the name "bulk read". They are are all read through handles. (*) From a drivers point of view (this software) there is no difference between an input (record) or an output record with READBACK. Both need to read the PLC variable and the result needs to go into the asyn parameter library, from where the records picks values up.
There are 2 ways to use the READBACK: Either by using "I/O Intr" or by a polling with 1 Hz. When an output record is processed, and the value pushed into the PLC, the PLC may decide to ignore the change in the next PLC cycle. And set back the variable back to where it was. As there is "no change" from a PLC perspective, the EPICS record and the PLC variable get of synch. There is no notifaction send via ADS (2 would have been better). As a workaround, the 1Hz poller can be used. Document this better.
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There is probably no fix possible. But a working solution for
#13