Help, new to AB SLC-5/03

I wonder if anyone can help. We have a SLC-5/03 PLC which controls 1 digital input card, 1 analog input card and 4 digital output cards.
The fault is that there are inputs present but NO outputs! Have hooked up a laptop to the plc and am able to go on line. Everything seems to be OK except that I'm sure the active rungs should be highlighted in green. These are in red. Is this correct? Have also tried to toggle an output bit - this works (it's corresponding red output led is lit).
Have fitted a new processor card as well but it's still the same.
Any ideas?

is the online button Red. Meaning fault?

Also how many LAD's are there. If there are more then one then you will need a JSR command with a U:3 for LAD3. I've never seen a red ladder in the default setup. But sounds like to me that you are not running the program.

Other things to try. Turn the key to Program them to run on the front of the PLC itself a few times. Sometimes it clears the fault. Mind you wont know what happened if you do this but it will get it up and running if its a resetable fault. If the Online button in the program is blue its in program mode. You need to turn it into run mode. You can turn the key to run on the front. If its Red its in fault condition. You can goto the fault by clicking on the red button and select goto fault or something like that.

Hope this helps a bit.

The online botton in rs logix 500 is green.
What do you mean by LAD?
Many thanks for your help.
I can see some timers working ie the enable and done lines highlight in red also when they are told to.
The thing is that everything appears to be OK but still no physical outputs!

Post your .rss file if you can. Zip it and post.
Is the processor going to a fault condition or are you saying the outputs will not come on.

The LAD is a file that the PLC runs. If you have something more then 1 LAD then you JSR command that Jumps to Subroutine X.

But sounds like you dont. It must be something with the program itself.

Like Mickey said zip it to the site and Hopefully we can look at it.

However I'm heading home so if noone gets and answer to you by then I'll look in the morning.

I'm afraid I can't post the .rss file - I'm at home now.

Don't know where to turn to for assistance!

I'm saying that the processor is not in fault condition and yet the outputs will not enable.

Ok then.

You said you toggled the bit right. That means the output is not in the program and isnt being commanded off.

Normally an output is turned on by a coil. This means in AB programming that if it isnt being activated when the program scan it the output is turned off.

You need to look for an output and see if it turns on in the program. If that happens and you dont get an output then more then likely its inhibited. Not sure if thats possible on SLC's but it might. If that is the case look at your I/O map (cant remember the exact name as I have shutdown the laptop) its in the program tree on the left twords the top. If you cant find it just keep click on stuff and closing it with the cancel button so in case you change something it isnt saved. Until you find the I/O stuff.

See if somethins inhibited. Not sure exactly what to look for but usually with AB there is a box with a check for inhibit or something like that when you click on the module itself or properties of the module. Not sure what else I can give you until we see the program.

Sorry if that doesnt help you.

Yes I remember that in the I/O information, the slots are laid out in rows and the bit patterns in columns.
I noticed that the correct bit patterns were shown for the inputs in the correct slots, but for the output cards all of the respective 8 bits were all set to 0 (off), even though the ladder logic shows some of them to be on.

HMMM? See below for what Chris s is talking about. Also see PDF for explaination. If this happend, then question is why/how?

Thanks for your help, I'm going to have to leave it now and try something tomorrow.

Mistersitter said:

... Everything seems to be OK except that I'm sure the active rungs should be highlighted in green. These are in red. Is this correct? Have also tried to toggle an output bit - this works (it's corresponding red output led is lit).
Have fitted a new processor card as well but it's still the same.
Any ideas?

Click to expand...

The default color scheme in RSLogix will paint the logic red when there is a fault present. Under those circumstances, you can toggle bits online, even in the output image, and they will change states in the CPU data table. The output card points will not be updated to match the output image, but I am not sure about the indicators on the cards. The O:x and I:x addresses are in the CPU and when faulted, the output cards will go to their fault state (usually off).

In RSLogix, look in the upper left hand corner at the CPU status indicator. If should say RUN, REMOTE RUN, PROGRAM, or FAULT...

If it is faulted, you can drop down the list of choices and hit GO To ERROR. Do this and take a note of the error fields before you clear the error and put it back in run mode.

Paul

If you are using subroutines, are they enable?

I've found the cause of the fault. A SCADA system is connected to the PLC using the RS 232 port. It was found to have a bad connection on one of the plugs. When I hooked up the laptop I had to remove the SCADA link to look at the PLC logic. It appears it was 'waiting' for communication from the SCADA system.
Would this be why the ladder shows up in red?
Everything's OK now. Thanks for your help.