Diagnosis bits

Depending on the selected Predefined PDO Assignment, the diagnostic bits are located in different process data objects.

In PLC control the diagnostic bits are located in the process data object STM Inputs Device. In PLC control extended, the channel-specific diagnostic bits are assigned to the channels’ process data objects.

Scope of the diagnostic bits	PLC control (Default)	PLC control extended
Device-specific diagnostic bits	STM Inputs Device	STM Inputs Device Compact
Diagnostic bits for channel 1	STM Inputs Device	STM Status Extended Channel 1
Diagnostic bits for channel 2	STM Inputs Device	STM Status Extended Channel 2

The diagnostic bits indicate warning and error messages.

Warning messages ("warning") are temporary.
A warning message indicates that a measured value lies outside of the nominal range. A warning message is canceled when the measured value is within the nominal range again.
Error messages ("error") are persistent.
If an error occurs, the affected motor channels are disabled until you acknowledge the error. See chapter Acknowledging errors.

There are two different scopes for diagnostic bits:

Device-specific errors and warnings affect the entire box module.
Channel-specific errors and warnings affect only one motor channel.

The diagnostic bits are divided into these two categories below.

Device-specific errors and warnings

If a device-specific error occurs, both motor channels are disabled. Both motor channels are re-enabled only after the device-specific error has been properly acknowledged. See chapter Acknowledging errors.

Bit name	Meaning	Possible reasons	Possible solutions
Device undervoltage	The supply voltage U_P is lower than the threshold value of the undervoltage detection.		Make sure that U_P lies within the nominal voltage range. Check the measured value of the voltage U_P in the CoE parameter F900:05_hex "Motor supply voltage".
Device overvoltage	The supply voltage U_P is higher than the threshold value of the overvoltage detection.
Overtemperature warning	The internal temperature lies above the warning threshold: Parameter F80F:04 Factory setting: 80 °C.	• The ambient temperature is too high. • The connected motor does not meet the specifications	Operate the device only within the specifications.
Overtemperature error	The internal temperature has exceeded the error threshold: Parameter F80F:05 Factory setting: 100 °C.		Operate the device only within the specifications.
General hardware error	The device is not able to initialize successfully.	The device is defective.	None.

Channel-specific errors and warnings

If a channel-specific error occurs, only the motor channel where the error occurred is disabled.

Bit name (PLC control / PLC control extended)	Meaning	Possible reasons	Possible solutions
Channel n openload / Open load	Wire break	• A motor phase is not connected correctly. • A motor phase has burned out. • Faulty triggering of wire break detection: The motor shaft was moved by an external torque when the motor was at standstill. ¹⁾(at enabled=1 and velocity=0)	• Check the motor connection. • Replace the motor if it is defective.
Channel n short circuit / Short circuit	At least one phase current has exceeded the value of the parameter “Maximal current”: see CoE parameter 0x80n0:01. The motor channel has been disabled.	• A motor phase is short-circuited. • The motor is defective.	• Check the motor connection. • Replace the motor if it is defective.
Channel n motor overload I2T warning / Motor overload I2T warning	The calculated I²T value is above the warning threshold: CoE parameter 0x80n0:16. Default: 80%	If this bit is set during the start-up phase: The output current is too high.	Reduce the value of the parameter “Sensorless offset scaling”: CoE objects 0x80n3:14.
If this warning message appears during continuous operation: Mechanical overload.	Reduce the load.
Channel n motor overload I2T error / Motor overload I2T error	The calculated I²T value has exceeded the error threshold: CoE parameter 0x80n0:18. Default: 110%	If this bit is set during the start-up phase: The output current is too high.	Reduce the value of the CoE parameter 0x80n3:14 “Sensorless offset scaling”
If this bit is set in continuous operation: Mechanical overload.	Reduce the load.
Channel n amplifier overload I2T warning / Amplifier overload I2T warning	The calculated I²T value for the motor output stage is currently above the warning threshold:	Incorrect parameter settings: The motor output stage typically reaches the warning threshold later than motors that meet the specifications.	Check the motor parameters: CoE object 0x80n0.
Channel n amplifier overload I2T error / Amplifier overload I2T error	The calculated I²T value has exceeded the error threshold:
Channel n in limit / In limit	The current is limited because the motor's I²T value exceeds 97%.	Mechanical overload	You can disable this protection feature by setting the CoE parameter 0x80n3:03 “Disable motor diagnosis” to TRUE.
Channel n commutation error / Commutation error	The commutation algorithm has determined that the rotating field and the rotor are not running synchronously. Hint: You can have “commutation errors” acknowledged automatically. See chapter Autoacknowledge: acknowledge errors automatically.	If this bit is set during the start-up phase: Mechanical overload ²⁾ The output current is too low. The “ramp-up velocity” parameter is set too high.	Check the motor load. Increase the value of the “Sensorless offset scaling” parameter: CoE parameter 0x80n3:14. Reduce the value of the “Rampup velocity” parameter: CoE parameter 0x80n3:19
If this bit is set in continuous operation: The speed (output variable “Velocity”) is too low.	Try again at a higher speed. Increase the value of the parameter “Start velocity” (CoE parameter 0x80n0:09) to ensure that the motor does not start with a speed setpoint that is too low.

Bit name

(PLC control / PLC control extended)

Meaning

Possible reasons

Possible solutions

Diagnosis bits 6: Channel n openload /

Diagnosis bits 7: Open load

Wire break

• A motor phase is not connected correctly.

• A motor phase has burned out.

• Faulty triggering of wire break detection: The motor shaft was moved by an external torque when the motor was at standstill. ¹⁾(at enabled=1 and velocity=0)

• Check the motor connection.

• Replace the motor if it is defective.

Diagnosis bits 8: Channel n short circuit /

Diagnosis bits 9: Short circuit

At least one phase current has exceeded the value of the parameter “Maximal current”: see CoE parameter 0x80n0:01.

The motor channel has been disabled.

• A motor phase is short-circuited.

• The motor is defective.

• Check the motor connection.

• Replace the motor if it is defective.

Diagnosis bits 10: Channel n motor overload I2T warning /

Diagnosis bits 11: Motor overload I2T warning

The calculated I²T value is above the warning threshold:

CoE parameter 0x80n0:16.
Default: 80%

If this bit is set during the start-up phase:

The output current is too high.

Reduce the value of the parameter “Sensorless offset scaling”: CoE objects 0x80n3:14.

If this warning message appears during continuous operation:

Mechanical overload.

Reduce the load.

Diagnosis bits 12: Channel n motor overload I2T error /

Diagnosis bits 13: Motor overload I2T error

The calculated I²T value has exceeded the error threshold:

CoE parameter 0x80n0:18.
Default: 110%

If this bit is set during the start-up phase:

The output current is too high.

Reduce the value of the CoE parameter 0x80n3:14 “Sensorless offset scaling”

If this bit is set in continuous operation:

Mechanical overload.

Reduce the load.

Diagnosis bits 14: Channel n amplifier overload I2T warning /

Diagnosis bits 15: Amplifier overload I2T warning

The calculated I²T value for the motor output stage is currently above the warning threshold:

Incorrect parameter settings: The motor output stage typically reaches the warning threshold later than motors that meet the specifications.

Check the motor parameters: CoE object 0x80n0.

Diagnosis bits 16: Channel n amplifier overload I2T error /

Diagnosis bits 17: Amplifier overload I2T error

The calculated I²T value has exceeded the error threshold:

Diagnosis bits 18: Channel n in limit /

Diagnosis bits 19: In limit

The current is limited because the motor's I²T value exceeds 97%.

Mechanical overload

You can disable this protection feature by setting the CoE parameter 0x80n3:03 “Disable motor diagnosis” to TRUE.

Diagnosis bits 20: Channel n commutation error /

Diagnosis bits 21: Commutation error

The commutation algorithm has determined that the rotating field and the rotor are not running synchronously.

Hint: You can have “commutation errors” acknowledged automatically. See chapter Autoacknowledge: acknowledge errors automatically.

If this bit is set during the start-up phase:

Mechanical overload ²⁾
The output current is too low.
The “ramp-up velocity” parameter is set too high.

Check the motor load.
Increase the value of the “Sensorless offset scaling” parameter: CoE parameter 0x80n3:14.
Reduce the value of the “Rampup velocity” parameter: CoE parameter 0x80n3:19

If this bit is set in continuous operation:

The speed (output variable “Velocity”) is too low.

Try again at a higher speed.

Increase the value of the parameter “Start velocity” (CoE parameter 0x80n0:09) to ensure that the motor does not start with a speed setpoint that is too low.

¹⁾ This happens, for example, when a package is conveyed from the previous zone and the package rotates the non-driven conveyor roller due to its forward movement.

²⁾ Especially likely when the motor makes a noise with increasing pitch.