FX1S Coils Not latching

[Tim Knowlden]

Hi, I am fairly new to PLCs, I am writing a gate/barrier autmation program, however I have Y0,1 & 3 Flickering and unable to signal their relays.

1 & 3 are barriers that need a pulse to open, 0 & 4 are gates that need to maintain to remain open.

If you see in this screenshot Y000 is not ON when it is being called by M1.

Yet in another image Y0004 is ON when being called by M1.

This is in a simulator but works the same on the PLC, If i erase the program I can manually force on ALL outputs and the relays activate.

[glavanov]

As a rule, you can use a specific coil (Y1 in your case) once in a program and you are useing it 3 times... Steps 41, 56 and 63.

Read the programming manual about "double coils".

Edited March 17, 2023 by glavanov

[Tim Knowlden]

6 hours ago, glavanov said:

As a rule, you can use a specific coil (Y1 in your case) once in a program and you are useing it 3 times... Steps 41, 56 and 63.

Read the programming manual about "double coils".

Thansk for the information, that has confirmed to me why changing that to only have 1 output worked when I tested. Bizarre though how Y4 worked okay with multiple uses.

[NewVeganic]

Just a heads-up that it's not bizarre how Y4 appears to work. It's all in the code.

The state of Y4 will determined by the last use of Y4 in the program. The previous instance would have no effect. 

[Tim Knowlden]

Okay so that helps then if I want to give certain coils priority too. 

Its working now as it should so I'm glad I now understand it a bit better.

Thanks 

[NewVeganic]

Tim,  DO NOT USE AN OUTPUT COIL MORE THAN ONCE.

That's an order! 

 

:)

 

 

 

[Ron_S]

You can actually double-coil in certain circumstances.

If they are within an STL sequence.

Even then though it's better to use M coils and a bit of that M coil to operate the Y output outside of the STL sequence.

[NewVeganic]

Ron, we can build up to that. I did consider mentioning that but I thought I'd keep it simple. 

[glavanov]

That's why I always recommend reading the manual in detail with the notes and so on.
Especially with the FX series, where it is full of sample programs.
Usually when you look for something specific you always learn more...
Something that fades slightly with the IQ-F series.

[Ron_S]

14 hours ago, NewVeganic said:

Ron, we can build up to that. I did consider mentioning that but I thought I'd keep it simple. 

Of course - it can be confusing but Tim has now said he understands the double coil rule. So I thought it fair that there are exceptions. :) 

 

[Tim Knowlden]

Thanks for thew advice guys, Dont worry I dont intend to add anymore than 1 output coil. the PLC is working perfectly now for my needs.