Omron PLC basic example problem

[jacintoanacleto 0]

Hi there, i am a student from portugal just now beginning to work in automation, and i've been given an omron plc to work with, more specific a cpu11 CJ1m and i can't do the most simple task, lighting up a led.. So, this is what i've done so far, i've managed to connect the plc to the cx-programmer through sysmac way, with a rs232 cable, then i made this ladder scheme you see in the image below and transfer it to the plc. The problem is that when it runs, the led that i've connected doesn't light up, but the led indicating that the output is enabled lights up.. and i've measured the volts in all outputs and there isn't any power on them.. Here is a picture so you can see what i'm trying to do.. Where am i failing ? Thanks in advance.

[Michael Walsh 268]

You have not connected output power to your output card. See picture below: +24 VDC needs to be connected to B8, 0VDC needs to be connected to A8, your LED needs to be connected to the output on one side and 0VDC on the other.

[jacintoanacleto 0]

Hi Michael Walsh thanks for your time and reply, i've tried later to give those +24 VDC on B8, the outcome was that all of the outputs suddenly had power, causing the led to light up on all of them, maybe i wasn't connecting 0 VDC properly to A8, i will run a few more tests today and come back later with a response. cheers

[jacintoanacleto 0]

Ok, so i've done some further research and found out that my output module is basically broken, at least my input module is working properly and tested some basic inputs. Thanks for the help Michael.

[IO_Rack 181]

Those output modules are not very forgiving to short circuit. Have you tried any other output besides 1.00? If your module was damaged due to bad wiring then it is very possible the others are OK... if you did not wire them.

[BobB 58]

Take the sticky labels off the top - the modules will overheat as they have no natural air flow.

[JordanCClark 0]

Also, consider upping your resistor size. Driving an LED off of 24VDC will be rather borderline with the 1k resistor. I generally use 1.5k-- still plenty bright, and protects your diode a little bit more.

[jacintoanacleto 0]

Will take that in mind. Thanks to everybody for the help :) cheers

[jacintoanacleto 0]

Hi again, i am once again asking for your help, i'm trying to make a copy of an older program i've made for siemens S7-1200, this should be fairly easy so i won't open another thread.. can anyone tell me how to achieve the same result ? Forcing the coil to set or reset the output ? thanks in advance! :)

[BobB 58]

I guess you mean set and reset - not force. Use the SET and RSET functions or KEEP.

[jacintoanacleto 0]

Researching through the forum, found this thread: http://forums.mrplc.com/index.php?showtopic=20084 I think it is the same issue, they seem to encourage to use the SET and RSET instructions, like this ?

[jacintoanacleto 0]

Hi Bob thanks for your reply, see my previous post. Is this the way to do it ? I couldn't have both of them in the same rung so i decided to separate..

[BobB 58]

It is possible to have them in the same rung - use N/O contact CF113 before your logic and combine the 2 rungs.

[jacintoanacleto 0]

Will do :) thanks again for the help!