Modicon TSX-Micro Double Coil

I came across a application recently, and noticed the use of a double coil.

My understanding of this is that this will not work, but I am not as familiar with the TSX-Micro as other brands.

In the attached file, the Control Section is before the Alarms section. The Compare %MW100>0 is an image of the attached HMI, so that any of the keys can initiate a fault reset, as well as a low->hi transition of %I1.7. After this rising edge trigger in the 1st rung of the alarms section, is where all the device fault logic is done, and where this reset bit appears.

Will this work?

How I understand it, you cannot reset faults from HMI, because reset bit %MW1:x0 will be first set to "1", but after alarms rung 1 bit %MW1:xo will reseted back to "0".

Because of that fault reset rung will see that reset bit (%MW1:X0) is zero and fault reset is not executed. (if fault reset rung is after "power up reset" rung)


Faul reset will work only with input %i1.7, because bit %MW1:x0 remains state "1" and until logic scan reaches control section.

Lare

Thats exactly what I though, but I'm not 100% competent with the TSX-Micro range, so want to be sure.

When I test this in another brand, it does not work as either, which is to be expected.

I am hoping to get back to site today/tomorrow to do some actual testing of this, but wanted to be sure before I tried too much more.

I'm not 100% sure either, maybe this kind logic works with PL7, but this is the way how it behaves with other types of Schneiders PLC (Unity, twido). I don't have PL7 series PLC now, so I can't test this.

Lare

I'm not 100% sure either, maybe this kind logic works with PL7, but this is the way how it behaves with other types of Schneiders PLC (Unity, twido). I don't have PL7 series PLC now, so I can't test this.

Click to expand...

No problem. But the PL7 is just a interface, it all compiles the same way, does it not. Or at least compiles for a certain processor type.

If this does not work when coding with a TSX-Micro in unity, it will not work with PL7, surely?

Scott,

I am not up-to-snuff on the later Modicons, but the only way I can see it working is if the Alarms sections happens to be a subroutine that is called before the Control section.

I am not up-to-snuff on the later Modicons, but the only way I can see it working is if the Alarms sections happens to be a subroutine that is called before the Control section.

Click to expand...

Yep, but unfortunately this is not the case. The Control section is before the alarms section in the application browser.

The main reason I asked, is the guys on site have said that this remote reset works, or has worked. For the life of me I could not see how, that is why I asked here...It seems that the general consensus is that it will not, which makes perfect logical sense!

I have quite a bit of experience with the PL7 Micro, but I think that your answer is more basic than that. You want to try to refrain from activating a coil in more than one location with any PLC, as doing so creates problems that are hard to diagnose. Most programs will let you do it without error, but it will never work as expected.

I attached an example of how I would do this.

I have quite a bit of experience with the PL7 Micro, but I think that your answer is more basic than that. You want to try to refrain from activating a coil in more than one location with any PLC, as doing so creates problems that are hard to diagnose. Most programs will let you do it without error, but it will never work as expected.

I attached an example of how I would do this.

Click to expand...

Thanks for your example, that's how I would of done it as well. For some reason, the operators on site said that this works, but I could not see how.
The other thing that I need to work out, is there is also another remote reset from a site-wide BMS, but I am waiting for those people to confirm what bit they are using to do this. They are convinced that the remote reset works as well, I have not been back to site yet, but am going to make the modifications as you have pointed out.