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RELAY OVERRIDE on WITH 24VDC Signal High, Low off


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I am not an expert in ladder logic. I am modifying some code and I need to code an override of a relay that is on O0 of the Jazz outputs. Im landing a 24VDC signal to I0. When the signal is high, I want the Relay to energize. As soon as the signal is low, i want it to de-energize. I have done this in V350 and Samba, but i cant get it to work on the Jazz. The closest I can get is with the reset and set coils. But that latches it. And it is two high signals that will turn it on then off. For some reason, when I replace the same logic with direct coils, i get no response. Please help!

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I downloaded this to the controller....ONLY that just to see if I could get the I/O to work...I get no response when I apply 24VDC to I0 (#15). Just in case I was mistaking about the physical address I applied the signal to all the Inputs...no response. If I jumer 24VDC O0 my relay energizes. Im overlooking something simple...please help. 

U90.png

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I have my power to the controller and the only thing I have actually wired to the controller are the outputs to terminals O-0, O-1, O-2, & O-3. The inputs, until I figure, I have left disconnected.  For the 24VDC signal I am just taking a 20 gauge wire and jumping V+ on the controller to the input I assigned. For example, with the ladder I posted above downloaded to my controller, I will run the wire from the number 1 position of the input terminal block, to the 15 position on the terminal block. 

If I simply change the coil to a set coil, it works to set the relay. But, as I stated above, as when I remove the 24V signal I need the relay to go off. With a set coil it stays energized. If I had my wiring wrong, I would expect it to not work with the set coil. 

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On 12/14/2019 at 12:17 PM, Flex727 said:

If you don't see I 0 on when you go online with the PLC then you have a wiring problem with your input.

Connect a jumper between 0V on the power and the n/p terminal (5).  The n/p terminal sets the voltage reference for the inputs as either sinking (0V = ON) or sourcing (+24V = ON).  

Since you are using a jumper from V+ to the input, this is considered sourcing.

Let us know if this works.

Joe T. 

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2 hours ago, Joe Tauser said:

Connect a jumper between 0V on the power and the n/p terminal (5).  The n/p terminal sets the voltage reference for the inputs as either sinking (0V = ON) or sourcing (+24V = ON).  

Since you are using a jumper from V+ to the input, this is considered sourcing.

Let us know if this works.

Joe T. 

That did it. Thank you all for your help.  I am a ChemE by education so I have some fundamental gaps I need to fill. 

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