🚀 go-pugleaf

I was wondering if anyone can help me with the following problem.

	I am currently working on a project to control pneumatic
valves via an existing computer output module.   The module outputs 24
volts to open, and ground to close the valve.  I also have solenoid
valves to operate my pneumatics.  This systems works as expected.
	The problem is that I am now building a control/manual
override board to be placed between the two units mentioned above.  I
plan on having an overide switch and a bicolor status LED.  The IDEAL
wiring would be:

        ******
input	*    *
----------   *
        *   -------------------------------------------------- output
  24 v----   *                          |
        *    *                     _____|_____
        ******                     |         |
    on-off-on toggle switch      green      /\    two wire bicolor LED
                                   \/      red
                                   |_________|
                                        |           560 ohm
                                        |_________/\/\/\/\/\____ 12 v
                                                            
	As I had FEARED might happen, when either the computer tries
to close the valve or I put the toggle to the neutral position the the
output floats to about 9 volts, which is enough to open the valve.  I
guess this is what happens when one makes assumptions about what one
is buying.
	Anyway, I would like a simple method to have my LED's sense
the status of the signal line with a higher input impedance.  Any
ideas would be welcomed.  I would like a simple idea, if available,
due to size of the project (40 valves).
	I am working on this problem here, but maybe one of you could
help. 

	email or posting, what ever is preferred.

		Sid Hellman
		sid@lamont.ldgo.columbia.edu