Diagnostic Monitoring

The controller performs both start-up and continuous monitoring of various conditions. A condition that is outside a normal range may cause the controller to automatically take mitigating action (e.g. cut back output power) or trigger a fault.

For clarity, the term condition refers to a specific status indication. A low battery voltage is an example of a condition. The term fault refers to a condition that causes the controller to inhibit motion, and requires a keyswitch cycle to clear.

So, for example, a throttle deadband check can result in a condition that inhibits motion, but it is not a fault. When the deadband condition clears (throttle moved back to neutral) the condition clears and motion is allowed.

Conditions

The following conditions are monitored and reported as status. Conditions are not exclusive (more than one abnormal condition can be reported at a time)

Controller Temperature

An onboard sensor measures the temperature of the controller near the drive electronics. As the temperature rises near the limit, the controller will indicate a high temperature condition and automatically reduce power. When the temperature decreases, output power will be restored and the high temperature indication will clear. See Controller Temperature Limit for more information.

Motor Temperature

When wired to a temperature sensor in the motor, the controller's ANALOG IN input monitors the sensor. There are two temperature thresholds. The first one causes the motor current to be reduced when the threshold is exceeded. The second (higher) limit will cause the motor to stop, report a fault, and require a key switch cycle before the motor will run again. See Motor Temperature Limiting for more information.

Under Voltage

The controller monitors the input voltage and compares it to two values: a threshold for displaying a low battery indication (Undervoltage), and a second threshold (Severe Undervoltage) that reduces the output power in order to extend battery life and potentially allow the vehicle to return to a charging point before stopping completely. When the voltage drops below the severe undervoltage threshold by a few volts, the controller switches off. Cycling keyswitch will turn the unit back on if the system voltage has increased above the severe undervoltage limit.

To troubleshoot an under-voltage condition, check for

• Depleted batteries
• Correct wiring between the battery and motor controller
• Correct configuration of the low-voltage limit.

Over Voltage

The system High Voltage Limit is configurable. If the system voltage increases toward this limit, the controller will report an overvoltage condition and will begin to limit the output power. When the over-voltage condition clears, power will be restored. A common situation that can lead to an overvoltage condition is heavy regenerative braking with a fully charged battery.

If the voltage continues to rise above the high-voltage limit, the controller will stop to protect the hardware from damage. The controller will resume operation when the over-voltage condition clears and (if Deadband Check is enabled) the throttle returns to a neutral position.

Current Limiting

If the output current to the motor exceeds the preset limit, the controller limits its output to prevent damage to the system.

Throttle Deadband Check

If configured to do so, the controller will not allow movement after power on, until the throttle has been detected to be in the neutral position. This is intended to prevent unexpected movement when the controller is switched on, and the throttle is not in neutral. Moving the throttle to the neutral position will clear the condition.

Other things to check:
- Correct configuration of the Throttle Deadband
- Correct configuration of the Throttle Neutral
- Correct configuration of the No Deadband Start setting.

Quickstop Active

The Quickstop input allows the external system to inhibit motion. The Quickstop signal is configurable; for example, whether it is active high or low, how quickly the motor decelerates when the condition occurs, and whether the keyswitch must be cycled in order to restore motion. See Register 0x0318 and Register 0x0353 for more configuration information.

Typically this condition means that a safety sensing device such as a seat switch, proximity sensor, emergency stop button has been activated. Check for
- A device connected to the Quickstop input indicating a stop condition
- Loose or broken connection to the Quickstop input
- Incorrect configuration of the Quickstop input

Motor Stall

A stall condition was detected using the motor position sensors. Check for

• Obstacles preventing movement
• Correct wiring to the motor and motor sensors.
• Correct configuration of the motor sensor(s)

The controller will continue to provide power to the motor during a stall condition.

CAN Bus Communication

If CAN Bus equipped, and CAN Bus is being used to provide control inputs, a loss of CAN Bus communication (too many missed messages or bus off condition) will cause the controller to inhibit motion. Re-establishing the CAN Bus connection will restore operation. Note: if the Deadband Check feature is enabled, the throttle must first be moved to the neutral position before motion is allowed.

Motor State

The controller provides a motor state output byte that is useful for monitoring the drive state of the controller. Its value is one of the following. See System Status Message for more information.

System State

The controller provides a status output that signals conditions in an abnormal range. It is possible for multiple conditions to be reported as out-of-range at the same time. See System Status Message for more information.

PWM Diagnostics

The controller provides a status message that contains information about what could be causing no PWM or limited PWM to occur. Multiple bits can be set. See System Status Message for more information.

Stop Diagnostics

The controller provides a status message that contains information about what caused the motor to stop. This is an enumerated value. Bits 0-3 contain the value. See System Status Message for more information.

Miscellaneous Diagnostics

The controller provides a status message that contains miscellaneous information about what could be causing certain faults or conditions. See System Status Message for more information.

Special Diagnostic Commands

Special diagnostic information on motor faults can be found by reading special RAM registers.

Charge Mode

The charge mode status byte indicates the status of the connected battery charger (applies to compatible chargers only). If the value is 0, the controller is not in charging mode.

Diagnostic Reports

There are several diagnostic records stored inside the controller's EEPROM. Here is a list of information available.

Note: If EEPROM Register 0302 Bit 2 is set, the address of the counters is OR'ed with 0x0080. For example the reset cause will be at 03E9 instead of 0369.

Identification

See Identity.