SandwichMagic
Member
So, we know that our outputs are working now! that is great. Now we just have inputs to deal with. So I am not familiar with AD's programming software, I imagine that the UDC is a counter? and the third rung is meant to clear it, yes? If so that all looks fine. The reason why the light is always on is in Rung #3. You have a set of comparative contacts which compare the status of the counter (I think) with 23, and those contacts close when the status of the counter (I think) is less than 23. The problem is that this is your only instruction on that line. It doesn't care whether you have hit the start button or not, you haven't told it to. All it is looking for is whether the counter is less than 23, and when you first turn on the PLC, it is 0, which is less than 23. You can remedy this by putting in a XIC tied to X1 as the first thing in rung 3.
Edit: Forgot to mention that you would need to add the same thing for rungs 4 and 5 as well, when you get your inputs working, the red and yellow lights will also not care. as a side note as well, I don't know how much turning the program "off" in this manner will help maintenance, I suppose you could ensure that power wont go to your lights but that's about it.
For your input problem, this link (http://www.automationdirect.com/static/manuals/d0user/ch2.pdf) is a link to the installation manual for your PLC, the inputs are on page 28 of the pdf. The diagram from the manual for your plc is on how to wire the inputs correctly. The manual says that you can wire it sinking or sourcing, so it doesn't matter if you decide to do it sourcing.
Edit: Forgot to mention that you would need to add the same thing for rungs 4 and 5 as well, when you get your inputs working, the red and yellow lights will also not care. as a side note as well, I don't know how much turning the program "off" in this manner will help maintenance, I suppose you could ensure that power wont go to your lights but that's about it.
For your input problem, this link (http://www.automationdirect.com/static/manuals/d0user/ch2.pdf) is a link to the installation manual for your PLC, the inputs are on page 28 of the pdf. The diagram from the manual for your plc is on how to wire the inputs correctly. The manual says that you can wire it sinking or sourcing, so it doesn't matter if you decide to do it sourcing.
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