How to debug ml1400

Hello every friend, I am a new learner for ML1400. I want to debug my programme. I try "test single scan", "continuous scan" mode. It doesn't make sense for me.
When I set "rem program" mode, the progamme is in the PLC proccessor? If it's really like that, what's the diffrence between this and "Run" mode when I edit some rung?
Other questions:
How to use "BSR" instruction to build subroutine progamme?
How to use "SUS" instruction to suspend processor? I try this instruction to debug, but it give me trouble and suspend my PLC proccessor. What's the suspend ID meaning? How can I use it?
Thanks in advance.

IMHO the only way to debug a program is to connect all inputs and outputs do a loop verification for all I/O ( test them all). Power up your system, make sure you know where the emergency stop is and make sure all personal are at a safe distance. Also have a fire extinguisher close by. Then put the processsor in the run mode and watch what happens.

"BSR"?? do you mean "JSR" see pdf below.

The "SUS" is used to trap and identify specific condition. There can be several of them in your program. The ID is used to identify which one ("SUS") was executed. Stored in status word S:7. You have to first decided which condition(s) you want to monitor and cause a "SUS" to be executed. I have never seen it used.
I would think it would be used to help find an ongoing problem not for a new program.

the best thing to do is to post your RSS program file (you'll have to ZIP it first - forum rule) ... we'll be glad to help you work through things ...

forget about the SUS ... I've been doing this for almost 30 years and never really seen a need for that one ...

and my distinguished colleague Mickey is correct - I think that you meant JSR instead of BSR since you mentioned "subroutine" in the same sentence ...

warning! ... if you're going to stay in this trade be EXTREMELY careful with your typing - and proofread EVERYTHING ... details - details - details ...

to answer a few of your specific questions:

When I set "rem program" mode, the progamme is in the PLC proccessor?

Click to expand...

actually as soon as you do the "download" operation, the program goes into the PLC processor ...

in BASIC terms ...

when the processor is in the Remote Run mode, it IS executing/scanning its program (the boss is making money) – AND – you can change the mode to the Remote Program mode from the computer keyboard ...

when the processor is in the Remote Program mode, it is NOT executing/scanning its program (the boss is not making money) – AND – you can change the mode to the Remote Run mode from the computer keyboard ...

secret handshake: the "remote" part means that you can make changes to the Run/Program mode setting from the computer keyboard ... specifically, the computer keyboard IS the REMOTE location ...

hope this helps ... welcome to the forum ...