Let's see, in this PLC ladder program, Y2's coil has an output.
But on the PLC control board, Y2 has no output, and the output indicator is not on, what is going on?
Let's take a look at the analysis of the majority of electrician friends:
Friend A: Is 24 and 0 reversed?
Friend B: There is no voltage in the output of Y2, first monitor the program, whether there is a double coil, SET, RST are allowed to double coil
Electrician C: Either the output port of the PLC board is broken, or the common end is broken, if it is all right, it is the problem of the internal relay, and the above problems can be measured with a multimeter
Electrician D: The wiring of the PLC output terminal is not the same as the point of the PLC program
Friend E: Could it be that there are two Y2 outputs in the PLC program? High probability double coil
Friend F: Use a multimeter to measure the output of Y2 and see, will it not light up when its output is on? If the output is normal, check the wire connected to Y2. If there is no output, it may be that the internal relay of Y2 is broken.
Friend G: Some people say that the electricity is burned, but it is impossible that the optocoupler is burned or the isolation circuit is burned
Subscriber H: Isn't there an indicator? If the indicator light is on, it is a relay problem. If the indicator light does not light up, there is a problem with the program.
Electrifier I: The indicator light is on, and it is possible that the diode inside is fine, but the triode is burned
Friend 1: It's good to change to a solid-state relay
Electrician 2: Mitsubishi has always had this kind of problem, and sometimes it can be solved in a mess by changing the relay or output point
Electrician 3: Dual coils, or change the output point to see if the output point is broken
Friend 4: If the voltage and line are normal, change the channel
Friend 5: Could it be that the relay is broken, change Y2 to SET Y2
Electrifier 6: I have encountered the same problem before, and then I checked the reason for the double coil, I don't know if you are like this, if not, the output point is broken, you can write a separate output to see
Friend 7: Rewrite a point, try, see if it's a problem with the program, or a hardware problem
Electrifier 8: If it is not a relay problem, it is possible to have a double coil, what is the big head, just check it one by one
Electrician 9: I think the best way to avoid humbuckers is to use set and reset commands
Electrifier 11: Y2's indicator lights are not lit, there are the following two situations, one is that the PLC program has a double coil, and the other is that the Y2 contact and indicator light are broken, but this situation is relatively rare, let's see if there is a double coil.
Electrifier 12:1、Write Y2 output directly,See if you can? 2. You get a blank Y point, such as Y3 or Y4, to test whether other programs of the double coil are stuck.
Dian friend 13: The first thing to check is whether it is a double coil, and when it is output at another point, compare, and use the elimination method when there is no way to deal with the fault
Friend 14: Find whether there is an output in the corresponding IO port test of Y2, if there is no chip change, if there is an external circuit
Dian friend 15: After testing whether the coil of the output relay has a voltage of 12V, then see if the power supply of the drive module of the board has a voltage!
What do you think, what is the problem? Welcome to leave a message and communicate in the comments
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