Wow thanks for the replies and diagrams.
The driver board is from a pinball machine, the 5vdc is for it to recognise a coin drop switch and not really relevant for the problem.
So a little update. I had another new relay and wired it the same way only with the 12 and -12vdc wires connected at the DC + and - from the relay which shouldn't be a problem how I see it (and the card reader booted) Last I tried to measure the pulse it had around 8.5 VDC. For some reason this also triggered the switch while set to low/GND. Which I thought was wierd.
Now for the worse part. The pulse wire also had a ground wire which was recommended but not necessarily needed to be connected.
After I held it next to the ground of the pin all machine it had a short spark which seems to have fried something in the card reader.
Card reader is Nayax Onyx

https://drive.google.com/file/d/1_bkeo5h_aJ6EOvfoGuStYk2-YQmxLeGs/view?usp=drive_link

https://www.google.com/url?sa=t&sou...CAwQAQ&sqi=2&usg=AOvVaw3C9f_idA4eX1yBe1NkuDkY

 

Well it seems you wired the relay module correctly in post #1 just as the Nayax manual suggested.
Is the relay module the same as seen in the manual, a dual relay?
There are 3 different pulse output modes available.
If you get the card reader fixed or a new one I would suggest using the Invert Pulse mode ( section 3.2.2 ) and set the relay module for high.
Are you sure the reader is damaged?

 

OK, but how do we know if there is an opto-isollator?? Unless it is that four legged IC device,

Those relays, when set to a "L" trigger, provide the DC+ via a 2.2k resistor (approx) and optoisolator to the "IN" pin. That is, it supplies the voltage at the "IN" pin for grounding to trigger the relay.
So the question is, can the card reader handle the approx. 9V (12V less opto LED voltage drop) at 4 to 5mA? If the card reader expected a 5V TTL level signal, then the TS may have blown the interface of the card reader. One would think the card reader interface would have a buffer device like a transistor or MOSFET to drive that line low for 25ms. In that case, that would be the device that has failed.
Since it worked twice, then failed, I agree with sghioto, the card reader interface may be at fault.
Was there a data sheet that came with the relay module that described what it does and how to use it?? Do we know if it is sourcing a current hat must be conducted to the common to operate the relay. Did a circuit of that module arrive with the data /spec sheet??? Where id those folks who appear to know how that module works gain that information???

 

OK, but how do we know if there is an opto-isollator?? Unless it is that four legged IC device,

Most of those cheaper relay boards use a chip similar to the PC817 (4 legged device), but a bi-directional one (PC814?).
When one selects "H" (high), the jumper grounds one end and user supplies the high voltage to IN to trigger. When one selects "L" (low trigger), the opto gets connected to the Vcc (DC+) and one grounds the IN to trigger.

 

Wow thanks for the replies and diagrams.
The driver board is from a pinball machine, the 5vdc is for it to recognise a coin drop switch and not really relevant for the problem.
So a little update. I had another new relay and wired it the same way only with the 12 and -12vdc wires connected at the DC + and - from the relay which shouldn't be a problem how I see it (and the card reader booted) Last I tried to measure the pulse it had around 8.5 VDC. For some reason this also triggered the switch while set to low/GND. Which I thought was wierd.
Now for the worse part. The pulse wire also had a ground wire which was recommended but not necessarily needed to be connected.
After I held it next to the ground of the pin all machine it had a short spark which seems to have fried something in the card reader.
Card reader is Nayax Onyx

https://drive.google.com/file/d/1_bkeo5h_aJ6EOvfoGuStYk2-YQmxLeGs/view?usp=drive_link

https://www.google.com/url?sa=t&sou...CAwQAQ&sqi=2&usg=AOvVaw3C9f_idA4eX1yBe1NkuDkY

The manual you linked to shows the correct connections with the 2 relay example. I wonder if your power supplies (12V and 5V) have different grounds, or are they all tied together as they should be? All grounds for the DC supplies and devices should be tied together.