Digital Inputs are not working

= Error Definition =
 * When I apply an input on the digital input, the PLC does not seem to detect it.

= Components To Be Checked =
 * Make sure the cabling and grounding is correct. See the hardware manual of your device for details.
 * Check your power supply. Measure the voltage levels at the Digital Input connector with a measurement device. The supply should be a DC voltage supply between 12/24 V.

= Possible Solutions =
 * The digital inputs of the PLC accepts voltage levels between 12-24 V DC
 * If you are using a 12 V power supply, it is possible that it cannot provide enough voltage to excite the digital inputs. Replace your voltage supply with a 24V and try applying the input again.