Before I start, please don't jump all over me for my question. While I have a good command of the english language, my understanding of electronics is VERY basic. I have done a search on my question, but lacking a PhD in electrical engineering, most of the replies went right over my head. I would appreciate if someone could answer my question in plain layman's language...
Here is my situation. I am converting an X3 mill using a Promica kit and the Gecko G540. The Promica kit includes optical homing sensors that operate on 5V. Here is a description of the sensors as provided by Marc, the owner of Promica.
"The optical sensor is basically a transistor that is operated by infra-red and the output will be ‘floating’ or pulled to ground (-ve) depending on the IR beam being there or not.
In my controller I use logic level signals ... I have a 5K resistor between the output and +5V. When the beam is broken the transistor stop conducting and the 5K resistor pulls the line high. When the beam is not broken the transistor conducts and pulls the line low.
Mach3 is configurable to see either state as ‘homed’ ... so you don’t have to worry about which state is ‘on’ or ‘off’ the switch – you can change it.
All you need is a 5 v supply across the Shield (-ve) and Red(+ve) wires and a resistor (around 5k) from the White(op) to +ve ... the White would also then be connected to any available input pin on the parallel port. I use a separate pin for each home (XYZA) but Mach3 can also handle a single pin for all..."
My understanding of Marc's explanation is that 5V is carried in a circuit from the 5V power source to the optical sensor. If the sensor is not obstructed, the current flows back to the negative pole of the power source. It does not flow to the output/signal line due to the resistor placed between v+ and the output/signal line. When the optical sensor is obstructed, current can no longer flow back to v- and therefore overcomes the resistor and flows down the output/signal line. So now the line goes high as there would be a 5V current in it.
The Gecko manual shows SPST relays connected to inputs 1-4 with an NC state. I assume that when the relay is open, the G540 sends a signal to Mach3 via the parallel port pins 10-13.
Now my questions. If I hook up the optical sensors to inputs 1-3 for my three axis, will it work? Will I fry the electronics because I'm sending current down lines that merely monitor continuity from the relays? (Input 1-4)
Should I bypass the inputs and tap into pins 10-13 on the parallel port? If I did, would this fry anything in the computer?
What is the best way to configure these optical sensors?
Please excuse my limited understanding of electronics, and if you would take the time to help, remember to speak in english, not electronese.
One more note aside...Is it possible to use the VFD to control the spindle speed of the X3 mill by sending the VFD output to the pot control on the mill. I have measured the voltage as 0-7 volts at the pot. Can the VFD output be limited to 7V so I won't stress the pot. Is there a way to configure that in Mach3?
Sorry for the long winded, multiple question thread. Thanks in advance to all:banana: