What is wrong with this SFC

[mister x 2]

I have been working at learning programming languages, and one of the books I have been reading has the following code.  But it doesn't run when I load it to a Softlogix CPU.  It won't go beyond the first step.  When I try to force the Tran_000 trigger (BACKWASH_START_PB) to a 1, it flips back to 0 instantly.  It's that tag that is the problem, because I made a tag not used elsewhere in the routine in it's place and it will run the program no problem.  What is wrong here?  thx

[ratcliffe_ic 2]

Step 0 is set to a type N - non-stored which means the code in the step is continually scanned, so every time you set BACKWASH_START_PB to a 1 the code in step 0 sets it back to a zero. 

If you click the square box next to the N you can set the Qualifier to Pulse (Rising Edge) which means the code in step 0 will only be scanned on the rising edge of the step becoming true.

 

[mister x 2]

Thx, that was a good first step to figuring this out.  The next problem is that the routine blows by the timer I set for Step_001 and goes straight through to the end.  Here is my setting downloaded to the CPU.  I thought this would pause at Step_001 for 30 seconds....?

[ratcliffe_ic 2]

Have a look at the TONR instruction