Two quick questions regarding sequencers and structured text.

[spaaw]

hi,
I looked on google and faq but with no result..
My questions are:

-how do i call a subroutine from structured text?

-i was looking at the sequencers and how they work.. how come its destination (dest) has only 1 output? (for ie. 0:2.0) when the array consists of multiple 'steps'?

thanks for the help

 

[TConnolly]

Use JSR to call a subroutine.

The sequencer moves one word from the array to the output at a time. When .POS is 1, it moves word 1 to the output, wen .POS is 2 it moves word 2 to the output, etc.

 

[Ron Beaufort]

also - you should realize that the "output" that you mentioned (O:2.0) is actually a "word" which is made up of 16 individual bits ... when you look at it from that particular viewpoint, the SQO actually has 16 outputs (output bits, that is) ... if you don't want to control all of those bits with the SQO, then you use the "mask" entry to tell the SQO to leave certain bits alone ...

 

[Clay B.]

hi,
I looked on google and faq but with no result..
My questions are:

-how do i call a subroutine from structured text?

-i was looking at the sequencers and how they work.. how come its destination (dest) has only 1 output? (for ie. 0:2.0) when the array consists of multiple 'steps'?

thanks for the help

The output only has 1 address because the programer was evil and did not want you to know what he was doing....j/k

The real reason is space. By setting as Ron mentioned in his responce you are actually working with 16 unique bit addresses.

When you write sequence like this your goal is to create a sequence that is very fixed and can not get out of time... IE what has to take place in Step 2 doesn't happen in Step 3... It is an efficent way to program but can have several pitfalls... Biggest is the guy behind you having a clue as to what you did... I reserve this type of programing for when I need scan speed or I have a very large range outputs that need to work together... Or I am just feeling lazy and want the debug guy to suffer...