Should $MOVE_ENABLE be assigned to an input other than $IN[1025]?

CELL.src:

LOOP
    P00 (#EXT_PGNO,#PGNO_GET,DMY[],0 )

Then, P00:

CASE 3
    ;*******************
    IF PGNO>0 THEN
        WAIT FOR  $IN[PGNO_FBIT+PGNO-1]==FALSE
    ENDIF
    K=0
    REPEAT
        FOR I=0 TO  PGNO_LENGTH-1
            IF $IN[PGNO_FBIT+I] THEN
                IF K==0 THEN
                    K=I+1
                ELSE
                    PGNO_ERROR=0
                    K=0
                ENDIF
            ENDIF
        ENDFOR
    UNTIL ((K<>0) OR (PGNO_ERROR==0))
    PGNO=K
ENDSWITCH

Here, P00 waits until $IN[33] is cleared. But then it immediately runs through the rest of the code, and ends up with K=0 and PGNO_ERROR=0. It returns these values back to CELL.src

Then back in CELL.src:

LOOP
    P00 (#EXT_PGNO,#PGNO_GET,DMY[],0 )
    SWITCH  PGNO ; Select with Programnumber

        CASE 1
            P00 (#EXT_PGNO,#PGNO_ACKN,DMY[],0 ) ; Reset Progr.No.-Request
            BasicLoop() ; Call User-Program

        CASE 2
            P00 (#EXT_PGNO,#PGNO_ACKN,DMY[],0 ) ; Reset Progr.No.-Request
            ;EXAMPLE2 ( ) ; Call User-Program

        CASE 3
            P00 (#EXT_PGNO,#PGNO_ACKN,DMY[],0 ) ; Reset Progr.No.-Request
            ;EXAMPLE3 ( ) ; Call User-Program

        DEFAULT
            P00 (#EXT_PGNO,#PGNO_FAULT,DMY[],0 )
    ENDSWITCH
ENDLOOP

The DEFAULT case is selected, which is the #PGNO_FAULT in P00:

CASE #PGNO_FAULT
    .
    .
    .
    .
    
    IF PGNO_ERROR==0 THEN
        IF (PGNO_TYPE==3) THEN
            MsgQuit("ProgNumberWrong", "P00")
        ELSE
            MsgQuit("ProgramNotAvailable", "P00", PGNO)
    ENDIF
...

This generates the "Incorrect program number" (i.e. "ProgramNumberWrong").

I can clear the message and it keeps popping up until after I resend PGNO bits, and PGNO>=1. Then it disappears. The motion program runs. Then, "Wait for not Input 33" shows up. Then, the bits are cleared, then "Incorrect program number" pops up. Then, I resend PGNO bits, and so on.

It's not a showstopper, but I would like to get rid of the "Incorrect program number" popup because it's a bit silly why it pops up, now that I understand the code.

I was wondering if I can fix this by assigning an input which I turn on from PLC after resending PGNO bits. Then, in P00 I can add a WAIT FOR this input to turn on:

CASE 3
;*******************
IF PGNO>0 THEN
    WAIT FOR  $IN[PGNO_FBIT+PGNO-1]==FALSE
ENDIF

WAIT FOR $IN[PGNObitsON from PLC]==TRUE

K=0
REPEAT
    FOR I=0 TO  PGNO_LENGTH-1
        IF $IN[PGNO_FBIT+I] THEN
            IF K==0 THEN
                K=I+1
            ELSE
                PGNO_ERROR=0
                K=0
            ENDIF
        ENDIF
    ENDFOR
UNTIL ((K<>0) OR (PGNO_ERROR==0))
PGNO=K
ENDSWITCH

This way, the code doesn't process K until new bits are available. Would this work?

Well, that was just one idea. I'm sure there are other alternatives.

Regardless of PGNO_TYPE, CELL loop is always running, and P00 is always looking for a PGNO input. There is no spot in the code to "do nothing until" - except if I choose to use the "Wait for not Input 33" for this purpose. So if I want to run my motion program just once, and let the robot idle for a while before I decide I want to move it again, I'd have to make some modification if I don't want to see those messages. It's not really "hiding messages", it's just creating a wait so that the code doesn't misunderstand in a hurry and throw this message.

Or, I guess I could make changes in SPS so that CELL itself is run just once until called again.

Folks, I'm happy to report that I have this working now

The "finishing touch" needed was a wait in P00.

CASE 3
;*******************
IF PGNO>0 THEN
WAIT FOR  $IN[PGNO_FBIT+PGNO-1]==FALSE
ENDIF


WAIT FOR $IN[200]==TRUE ;This is $EXT_START


K=0
REPEAT
    FOR I=0 TO  PGNO_LENGTH-1
        IF $IN[PGNO_FBIT+I] THEN
            IF K==0 THEN
                K=I+1
            ELSE
                PGNO_ERROR=0
                K=0
            ENDIF
        ENDIF
    ENDFOR
UNTIL ((K<>0) OR (PGNO_ERROR==0))
PGNO=K
ENDSWITCH

So now, after completion of the motion program, control goes back to CELL, and I see a message "Wait for Input 200". It stays in this idle state until I start my PLC sequence for sending it a PGNO. No more pesky "Incorrect program number" messages, because it knows to wait until it has received a new PGNO. It's silly to begin with, that they haven't written the code to handle idle state. Seems like an improvement item.

I'm glad to find that the code is customizable to my specific needs.