fons04 said:
...allen bradley input card...each input isolated sink/source possibility...terminal GND1...IN1...+24Vdc powersupply...
Based on the information you have provided thus far, I'd hazard a guess at this input module being a 1756-IB16I?
If so, then the following are the main Technical Specifications for this particular digital input module...
Inputs - 16 individually isolated
Voltage category - 12/24V DC sink/source
Operating voltage range - 10…30V DC
Input voltage, nom - 24V DC
Input delay time (screw to backplane)
Off to On - Hardware delay: 1 ms max + filter time
User-selectable filter time: 0 ms, 1 ms, or 2 ms
On to Off - Hardware delay: 4 ms max + filter time
User-selectable filter time: 0 ms, 1 ms, 2 ms, 9 ms, or 18 ms
Current draw @ 5.1V - 100 mA
Current draw @ 24V - 3 mA
Total backplane power - 0.58 W
Off-state voltage, max - 5V
Off-state current, max - 1.5 mA
On-state current, min 2 mA @ 10V DC
On-state current, max 10 mA @ 30V DC
Input impedance, max 3 kΩ @ 30V DC
Note: Only reference the above On-state values if you have confirmed that the input module is a 1756-IB16I.
So for this particular input module, any value at or above 2 mA @ 10V DC will switch the input channel ON.
Regards,
George