LaserUser.com Forum (formerly RDWorksLab)

HI. I have an RDC644XG controller in the laser cutter I'm building. I also have a water flow detection device which has a simple switch inside. Connection made when water is flowing.

I'd assumed I could just connect to the controller but having looked at the manual but now not so sure it's that simple. The diagram shows a water chiller with a 'water protect switch' two wire connection to the controller. The manual goes on to describe the connection thus:

"The input port of water protector for the first laser power source.
When the water protector 1 is enabled, the controller will detect
the input port of water protector 1. If this port is of low level, it
will be deemed normal; if this port is of high level, the controller
will forcibly close the laser to suspend the work in progress and
the system will warn. If the water protector 1 is not enabled, the
controller will not detect the input port of water protector 1 and so
the water protector 1 can be unconnected.
Water protection input must be 24V logic level."

So, can anyone confirm that I can't simply connect the switch across the terminals. What do I have to do - provide a switched 24v input when the water switch is closed??

As you know from the diagram, the switch goes between WP1 and GND [Earth].

If the switch is closed (WP1 = 0 [GND]), then the laser will work.
If the switch is open (WP1 = Z), then I assume an internal pull-up will cause the input to be '1 and the laser will not fire.

I don't think you can just connect the wires across the existing terminals. I just went through this when I wired in my CW-3000 to my circuit. There may be a better way to do it, but I ended up using a relay board and the existing cabling to add the water protection. It was a pretty straightforward install.

https://www.amazon.com/gp/product/B00LW ... UTF8&psc=1

RuiDa controllers control the ground, not the positive. Your connection would be between the 5V and the WP, not between the WP and the ground.