How to Wire Analog Inputs of Ace PLC

Ace PLCs are available with some number of general analog inputs. Ace PLC analog input interfaces are available for either 0-5VDC, 0-10VDC or 0-20mA.
Analog inputs are normally used to connect to transducer outputs. Such transducers measure some physical parameter, such as pressure, temperature, liquid level, position, pH level, or other such continuously variable measurement. The transducer signal output should be connected to a signal input on the Ace analog port and the transducer return or ground reference line must be connected to the PLC ground, next to signal 1 (or otherwise connected to the PLC’s ground).
Ace PLCs with current input analog input ports (part number ending in ‘c’) should be used for analog current signals between 0 and 20 mA. The two most common type of current signals are 4-20 mA and 0-20 mA. Full range analog signals will convert to a value between 0 and 4095 (12 bits). For 4-20mA inputs, the converted value will be between 820 and 4095. The Scale function in vBuilder can be used to automatically convert the signal value to meaningful data.
For PLCs that have a full 8 position port dedicated to analog inputs, the pin next to the sixth input is connected to the PLC’s internal 5V, through a 10 ohm resistor and a diode. This is provided to power a future analog input simulator. It servers no other purpose and should remain unconnected for application use. Analog input ports that do not occupy the full 8 position port do not have this connection.

Find this information in the Ace User Guide