FFL Instruction, use without having to toggle it's EN bit?

[jds8086]

EDIT: I suppose i should mention, RSLogix 500 V8.40, SLC 5/04 (1747-L542C)

Is there is a way to use the FFL instruction in a way that doesn't require its EN to have to toggle between true/false for it to load the next value? I have it in a subroutine that runs conditionally (logging events that are to be read via OPC and stored in a DB). Each "log-able" condition is checked in another subroutine that runs unconditionally, when a condition is met, JSR -> FFL subroutine, then it returns to continue checking other log-able conditions. It is important that each condition is checked every scan and stored in the buffer if true (hence why it's in it's own subroutine so that I can JMP to and return to continue evaluating other conditions).

 

[drbitboy]

EDIT: I suppose i should mention, RSLogix 500 V8.40, SLC 5/04 (1747-L542C)

Is there is a way to use the FFL instruction in a way that doesn't require its EN to have to toggle between true/false for it to load the next value?

No, but that doesn't mean you can't reset the .EN to 0 on a rung or branch before each FFL execution, and then execute the FFL unconditionally.

 

[jds8086]

No, but that doesn't mean you can't reset the .EN to 0 on a rung or branch before each FFL execution, and then execute the FFL unconditionally.

Ever spend hours on a problem, give up and ask, then when you get the answer you just want to hide

Thank You!

 

[ASF]

That's actually similar to a problem posed to a colleague of mine who went through RA PLC programming training. How can you make a single, standard counter instruction count the number of PLC scans with one rung of code?

|
|                         +-----CTU------+  My_Ctr.EN
|-------------------------+ CTU   My_Ctr +----( U )---|
|                         + PRE 99999999 +
|                         + ACC        0 +
|                         +--------------+

 

[drbitboy]

Ever spend hours on a problem, give up and ask, then when you get the answer you just want to hide

I'd answer that, but I am busy hiding just now.

P.S. I know you got it, but I already found an example using BSR (similar to FFL i.e. uses Control R-file element).

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