This image refers..

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This is an example of two open-collector drives from the "Deviation counter clear input" and "Command pulse inhibit input". This is just an example intended by the author to show how to switch the input. The real needed behaviour is shown inside the servo controller - there are two corresponding opto-isolators, each with a 4.7k resistor for current limiting. The anode (+) of each LED inside each opto is connected through the resistor to the 12-24V supply, and the cathode (-) is switched to ground by the input circuit - depicted as an open-collector driven system. That works, and should work well. If the driving BJT is ON, the open-collector output is drawn to ground, which allows the LED in the opto isolator to switch the internal gubbins. If the driving BJT is OFF, there is no current path for the opto-isolator LED, and the switches off the internal gubbins.

You are not required to drive using an open-collector output, but you are required to provide a current path to ground (or something substantially lower than the COM+ pin), you could use a push-button connected from the input to ground perfectly well.

More likely, you'll be using the MB3

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"Sink" refers to the ability to allow current to "sink" to ground. If you see the term "source" - it refers to the ability to source current from the +V supply.

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This shows that the MB3 has a number of open-collector outputs available to you.


"Is it me or is the Panasonic manual confusing on purpose?"

I was about 6 year old when my old man got me interested in Electronics. I'm now 51. I still have to read and re-read manuals like this.

The problem is that the manual is trying to convey a lot of basic information in as concise way as possible. They're not going to hold your hand to explain things - you're playing in the professional world where you're expected to know what you're doing. Not all of us do. Ask questions.

and, trite, but :

The dumbest questions are the ones that you don't ask.