Understanding 5069-ob16/dual outputs

[Bobobodopalus]

Hello all,


I've ran into a problem where we are trying to give a solenoid 2 inputs and this is causing a problem on the output card.


as you can see on the below image wire 45 can have an outside 24v on it, i have found that when this happens output 7 is activating, does anyone know why this happens?



https://imgur.com/a/3yKrez8


i assume i may have to insert an OR gate or a diode or something to this circuit to prevent it

 

[Bobobodopalus]

sorry i take it back about output 7 activating, the plc was outputting on 7, the problem is that this 24v is supplying SA power to the output card when the button is pushed which i need to avoid as the terminal 16 power is controlled by a safety pilz, thepush button sends a door down and then when it is closed the output card is given power which the plc will then latch the door power keeping it down

 

[chelton]

Output 15 should be driving an auxiliary relay, with the c/o contacts of the auxiliary relay in parallel with the push button. This will keep the supplies isolated.

 

[Bobobodopalus]

yeah, seems a bit obvious now the output isn't activating, would there be any issue using a diode in here instead of adding a relay?

 

[saultgeorge]

yeah, seems a bit obvious now the output isn't activating, would there be any issue using a diode in here instead of adding a relay?

+1 for Chelton. I would definitely add a relay. Also have you verified how much current the solenoids are drawing? I know they only fire one at a time however myself and I would presume others on here have fried relay output contacts or blew the fuse, causing unnecessary downtime or equipment expense. Hope this helps.