Light Beacon Not Working

I had a light beacon installed on my PLC which would go off when a fault occurred. Since last week it has stopped working. What do you guys suggest I should do to begin in order to identify the problem. What things should I check.

Thanks for your help!

Follow the wire or check the wiring diagram to figure out which Output on the PLC the beacon is wired to.

The use the Cross Reference or Search feature in the PLC software to find the rung that contains the Output. You can troubleshoot from there what conditions are no longer making the beacon run.

If the output associated with the beacon is turning on, but the beacon is not lighting up, check fuses and wiring and the bulb.

If the beacon was also associated with a horn, and it went off frequently, it is very common for these to be intentionally disconnected by people who want a little peace and quiet in the workplace.

No faults to announce?
Power to the unit Ok (Is it plugged in)?
Burned out bulb?
Broken or disconnected wire between the PLC and the beacon?
Is the PLC running?
Program in the PLC wore out?
Ambient light level in the room so bright that you can't see the difference between beacon on and off?

Seriously:

Can you reliably create a fault condition?
If so, create one and look at the LEDs on the PLC's output module to see whether or not the PLC is turning the beacon on.
If it is, the problem is between the PLC output point and the beacon.
If it isn't, the problem is that the PLC is not detecting the fault.
That all assumes it used to work correctly and now it doesn't. The longer it has been working correctly, the less likely that the problem is something wrong with the program.

Thanks guys I will try doing most of this. This really helps, thanks again.

In my expereince the most common causes of problems like this from most to least frequent are:

Loose or broken wire
Field hardware issue - blown fuse, bad bulb, failed power supply etc.
Program issue (unlikely unless someone has just "upgraded" the logic
Bad I/O card
Failed CPU

Start trouble shooting in that order, starting at the field device by checking for voltage and work you way methodically back up the chain.

Ken Roach said:

If the beacon was also associated with a horn, and it went off frequently, it is very common for these to be intentionally disconnected by people who want a little peace and quiet in the workplace.

Click to expand...

If it is in a production environment..........that is my bet. Followed by " I don't know what happened"

I'm willing to bet it's either been unplugged, or the bulb is dead. Who made it and what's the part number?

studentplc1,
Just last week you where asking about ordering a light beacon and now its already broke.(see link)

http://www.plctalk.net/qanda/showthread.php?t=53273

All do respect ( I sincerely mean that) if this is a real problem then you need some on site help. Trouble shooting a light bulb is pretty basic stuff. If you don't have the knowledge to do so be careful electricity can kill you.
Your handle says "student" is this some kind of classroom project? Maybe I'm reading to much into this.

No actually I am working at a plant as a student. The electrician was on vacation so I was thinking to try and see what the issue is. My previous thread was also a project given to me, I have ordered that beacon for another line.


But don't worry, any time I do anything I will be sure the electrician is there to observe.

studentplc1 said:

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But don't worry, any time I do anything I will be sure the electrician is there to observe.

Click to expand...

You have passed the first test. SAFETY.

What heppened to this?

Broken bulb?

Actually, when the electrician and I went to look at it, we found that it had a burned odour to it. A resistor in it also seemed to have melted. The whole unit probably has to be replaced .