asyn:READBACK making aao record process

[Marco Filho via Tech-talk <tech-talk@aps.anl.gov>]

Hi, all. One more question about asyn:READBACK:

I have an IOC with two array records (one aai and one aao):

record(aao, "$(P)$(R)$(RING)$(NODE)$(HYB)$(VMM)$(CH)-S") {

field(DESC, "Set $(CH) channels array")

field(DTYP, "asynInt8ArrayOut")

field(NELM, "64")

field(FTVL, "CHAR")

field(SDIS, "$(P)$(R)#$(RING)$(NODE)$(HYB)CalcDISA")

field(OUT, "@asyn($(PORT),$(ADDR),$(TIMEOUT))HYB_$(HYB)_$(VMM)_$(CH)")

#info(asyn:READBACK, "1")

info(autosaveFields, "VAL")

}

record(aai, "$(P)$(R)$(RING)$(NODE)$(HYB)$(VMM)$(CH)-R") {

field(DESC, "Get $(CH) channels array")

field(DTYP, "asynInt8ArrayIn")

field(NELM, "64")

field(FTVL, "CHAR")

field(SCAN, "I/O Intr")

field(PINI, "YES")

field(SDIS, "$(P)$(R)$(RING)$(NODE)Acquire-R")

field(PHAS, "1")

field(INP, "@asyn($(PORT),$(ADDR),$(TIMEOUT))HYB_$(HYB)_$(VMM)_$(CH)")

}

And they seem to work out fine. However, when adding asyn:READBACK to the setpoint and putting a SCAN period of 1 second to the readback, I get a few weird behaviors.
First, the setpoint record starts processing every second (which doesn't happen for other non-array records with READBACK tag):

dbpf LAB-MARCO:NDet-VMM:000000SC-S.TPRO 1

DBF_UCHAR:          1 = 0x1   

scanOnce: dbProcess of Disabled 'LAB-MARCO:NDet-VMM:000000SC-S'

spare-ipc-02-3293375 > scanOnce: dbProcess of 'LAB-MARCO:NDet-VMM:000000SC-S'

scanOnce: dbProcess of 'LAB-MARCO:NDet-VMM:000000SC-S'

Second, and harder to describe, is that after a process called by my device API (which should have no interference in the EPICS module/driver) the arrays seem to become unresponsive: if I try to put values into it, they are immediately overwriten by the old values:

$ caput -a LAB-MARCO:NDet-VMM:000000SC-S 4 1 1  1 1

Old : LAB-MARCO:NDet-VMM:000000SC-S 64 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

New : LAB-MARCO:NDet-VMM:000000SC-S 64 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

(vmm) marcofilho@spare-ipc-02:~$ caget  LAB-MARCO:NDet-VMM:000000SC-R

LAB-MARCO:NDet-VMM:000000SC-R 64 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

What is happening here? Is there a more proper way of doing this?
I tried changing the records to waveforms but didn't have much success...

Thanks in advance for any help,

Marco