Testing Digital Outputs

Most of the Digital Outputs on Enovation Controls displays are Low Side FET drivers, meaning they switch the negative side of the load circuit. Some of the outputs on the Powercore Controllers are high side drivers, they will be labeled as HS (High Side) or B+ outputs. It is important to know which output you are working with.

IMPORTANT: Inductive loads (relays and solenoids) generate a back EMF voltage spike of several hundred volts when the output is switched off and the coil gets de-energized. This voltage spike must be suppressed by using a flyback diode connected across the coil in reverse polarity. Failure to do so may lead to a damaged output FET and the voltage spike will travel down the wire and couple with adjacent wires in the harness leading to other system failures or anomalies.

Testing Low Side Outputs:

Step 1 - Verify Circuit Functionality: Use a simplified test Configuration with two buttons controlling the ON/Off state of the output. This will help verify the electrical circuit is working properly (Example Configuration). The intended load must be connected in this test. Measure DC Voltage between the output and ground. With the output in the "Off" state the measured voltage will be Battery Voltage. With the output in the "On" state the voltage will be 0Vdc. If the load specifications are not available you will need to measure the load current using a current meter to verify it is within the allowable limits of the output. If there is any doubt before performing this test disconnect the output and run the load straight to ground through a current meter before using the FET output.

Step 2 - Verify Configuration: Once you have performed step 1 and verified the circuit is functional you will need to verify the configuration functions as expected by testing the button actions, states, and events that are associated with the output. This will need to be done with a load connected. If performing a bench top test a simple indicator lamp will suffice. Connect Powervision to your display using the LAN and launch the Remote Monitor, this will enable you to monitor variables and fire events as part of the test plan.

Testing High Side Outputs

Testing a high side output is similar to that of a low side output with the exception that a load is not needed on the output to check its state,  simply connect a Voltmeter to the output to determine if the output is on or off.

Step 1 - Verify Circuit Functionality: Use a simplified test Configuration with two buttons controlling the ON/Off state of the output. The intended load must be connected in this test. Measure DC Voltage between the output and ground. With the output in the "ON" state the measured voltage will be Battery Voltage. With the output in the "OFF" state the voltage will be 0Vdc. If the load specifications are not available you will need to measure the load current using a current meter to verify it is within the allowable limits of the output. If there is any doubt before performing this test disconnect the output and run the load straight to Battery + and through a current meter before using the FET output.

Step 2 - Verify Configuration: Use the same procedure as in the Low Side FET, you may use a voltmeter to indicate if the output is on or off instead of a actual load.