Poka-Yoke

[dlewis]

This is the reason for my inquiry into SHIELDS.

We have several systems that use multiple Plus+1 controllers. Many of them utilize the same hardware with different programs in different locations on the machine. (Our largest system uses 10 displays and controllers) We had two occasions lately in which the wrong controller was placed in the wrong location on the machine.  As you can guess, this caused an issue.  Thankfully, no one and nothing was hurt.  But it brought to our attention, that this is an issue.

Does anyone have any brilliant ideas on how we can Poka-Yoke the harness location with a programmed controller?  I've got a couple of ideas, but I was wondering if anyone else has something they've used successfully.

[ramzilla]

You could use a resistance input, if available, on each controller and assign a resistance value to a known source address. If the source address and resistance value do not match you could disable the system and alert the user that the hardware is in the wrong location.

[dlewis]

That was one of my ideas, but rather than resistive input, it would need to be a voltage since many controllers don't allow a resistive input.  To use resistors, I would create a voltage divider and use that as a input into an analog pin. This is where I was hoping to use the "shield" pin since on many controllers I'm using all the input pins.

[Marbek_Elektronik]

I think, in start procedure you can check the controller positions:
When starting, there are specific inputs or voltages or currents on output pins.
Measure them or check them.