Siemens LOGO

[ward]

At the risk of being way off topic for this forum, here goes...
I'm installing some relay boards and trying to control them with a Siemens LOGO which is a small plc.

The relay boards have 12 relays that are tied to each other over a common V+ (24V).
Now, I bought a LOGO with transistor outputs (24V) ...
transistor output LOGO

With my previous cabling I had relayoutputs on my logo and I basically used them to open a path to ground.
Now, I don't see the way I can use these transistoroutputs to switch my relays ?
They don't switch to ground, even if they're on digital zero, they're not connected to ground.

thanks, ward

 

[gyraf]

..need more info on what it actually outputs. The link does not shoe or mention anything on this.

Perhaps add simple external open-collector transistor stage?

/Jakob E.

 

[ward]

..need more info on what it actually outputs. The link does not shoe or mention anything on this.

I'm not sure how to answer that:
My test told me that a digital zero is about 0.4Vdc.
A digital 1 is 24Vdc.

 

[ward]

this is what the outputs look like,
Maybe that helps in identifying what it actually does?
The T4140 is an N-channel mosfet.
T4140

 

[ward]

Perhaps add simple external open-collector transistor stage?

Could this be as easy as slapping a ULN2803 on the output ?

 

[gyraf]

Maybe.. What sort of output is expected from this box?

 

[ward]

Thanks for your answer Jakob, but I’m afraid I don’t understand the question.
Maybe this drawing explains better what I’m actually doing.
The problem is that i can’t switch the relayboard with a positive pulse since there’s a positive common.