CLX program scanning

Are programs in the same task scanned in parallel or sequentially? I'm used to stuffing everything into a single program and looking to better organize.

Thank you.

Programs run sequentially.

OG

Hi

if it's a routine you are talking about then It actually depends on your JSR instruction. The plc will scan the main program and from here it will jump to the different routines based on the position you place the jsr. you could actually have a jsr in a routine to call another routine without returning to the main routine.
If it's the program the It calls them in the order they are in the project tree which in logic 5000 you can move them around. But if it's a task you are talking about then these can be called by a event, by time etc.
Sorry for the answer not been straight but sometimes in hear people talking about programs when they actually mean a routine or a task


Donnchadh

einnh said:

Are programs in the same task scanned in parallel or sequentially? I'm used to stuffing everything into a single program and looking to better organize.

Thank you.

Click to expand...

Absolutely nothing in the Logix5000 stable (ControlLogix, GuardLogix, CompactLogix, FlexLogix, DriveLogix, or SoftLogix) runs or scans programs "in parallel".

All of them use a microprocessor that is single-threaded, and it can only execute each macro code for each instruction sequentially.

In the Cyclic, or Continuous Task, therefore, you define the order of operation of each program with the Task's Program Schedule, and the task executes the programs sequentially.

When another task (Periodic or Event) is triggered, processing of the Main Task is "interrupted" while the controller executes the other tasks.

As hinted by Donnchadh, the processor ONLY executes the routine defined as the Main Routine for each program - other routines are "called", as required by the programmer, by using JSR and FOR instructions, for example.

einnh said:

Are programs in the same task scanned in parallel or sequentially? I'm used to stuffing everything into a single program and looking to better organize.

Thank you.

Click to expand...

The Programs in a Task execute sequentially, in the order that the programmer placed them in (not a "program" thing...a configuration thing).
The Routines in the Programs execute according to the commands in the "routine assigned as Main".