Combination analog inputs and analog outputs
|Certain ACE PLCs have a single connector with both analog inputs and outputs.
The connections are as shown on the diagram at the right.
There is no need to connect anything to pin 8 (VA). It is like pin 8 on the digital input and output ports – connected to 5V via a 10 ohm resistor and a diode.
If connecting to an analogue output causes the CPU to reset, this suggests that the external connection is drawing a lot of current. Adding an in-line resistor will limit the current, but if the device to which it is connected is drawing a lot of current, the voltage after the resistor will probably be reduced. Try measuring the voltage at the input and output of the resistor.