Resistor Switching - Sensitivity

[gorblimey]

Hi Guys,

Thinking of purchasing one of your great 204 I/O Modules for a project.....just a quick question as to the input A/D sensitivity.

I'm essentailly thinking of running a circuit with a bank of 28 resistors in parallel with each being able to be 'switched' out as required to vary the output voltage.

Do you have any specs on voltage input/outputs i.e would it be sensitive enough?

Hope this makes sense?

Many thanks.

GS

[jason]

It's a 10-bit ADC across 5 volts.  Assuming you are referring to an incremental resistance style circuit and not a 28-bit resistor ladder, I think it would work for you.

A 28-bit R-2R resistor ladder would not work very well. 

[gorblimey]

Thanks for that Jason (and the link) and assumed right...my design relies on just the incremental/total resistance of the circuit though it would be exponential and I would hope to capture the voltage range for each resistor being switched out to 'detect' the change (not concerned about which resistor is switched out and would all be the same value)

Thanks again,

Gareth