enable outputs as if they were an array

[realolman]

SLC 500

is there a way to turn on outputs as if they were an array? Or something similar?

Right now I have a 16 output card and am comparing the count of a counter using EQU instructions on 16 rungs, and turning on each output according to the results of the EQU.

It works, but I feel like a hack (which I am, but I don't like feeling that way)

is there a more elegant way of doing this? Turn on each output one at a time for about 2 seconds at a time?... what I'm doing is checking to see if the card is good

thank you

 

[realolman]

I figured out how to do it.... sorta ....with a FLL

 

[cbuysse]

You could use an integer, with an initial value of 1, that doubles every two seconds. Continually MOV that value of that integer into the output word. It would work for the first 15 outputs, but the last one would have to have a different solution.

 

[Ron Beaufort]

first rung
XIC S:42/1 MOV -1 O:1.0

second rung
XIO S:42/1 MOV 0 O:1.0

this assumes that your SLC's clock is running – and that your output module is in slot #1 ...

they'll ALL go on and off at the same time – but if you're just trying to check whether the outputs are good or not, that should be enough ... two seconds on – then two seconds off ...

we usually put this right at the end of Ladder #2 when we test modules in the class ...

 

[Lancie1]

Another good tool for this is a Sequencer Output (SQO). You can load the Sequencer File with a binary series of 2^n numbers (1, 2, 4, 8, 16, 32, and so on up to 2^15 or 32768), then use a 2-second timer to trigger the SQO every 2 seconds, to turn on each Output in sequence.

I can post an example of the above, if you need it.

 

[realolman]

thank you all

 

[Bit_Bucket_07]

Bit Shift Left

 

[chelton]

Indirect reference the bit number with the counter accumulated value.
OTE O:0.0/[C5:0.ACC]

 

[daba]

There is an instruction in all SLC and Micrologix processors that does this for you....

DCD

Takes a 4-bit "value", and decodes it to one of sixteen output bits.

The 4-bit value (0 to 15) is the lower 4-bits of the Source word.

Unlike the indirect addressing that chelton suggested, this won't bomb-out if you have other bits set in the source word.