Recognize short circuits on CAN bus ALE Error images

The robustness of the CAN bus is also based on its tolerance to short circuits occurring.

Below we summarize the possibilities and show how the CANtouch detects these errors.

CAN bus error short circuit

Case	Description	Communication	CANtouch Bus status	CANtouch CAN level Absolute	CANtouch Measurement Participant	CANtouch Bus wiring
Ok	CAN bus without error	Yes	CANtouch_CAN-Bus-OK_Busstatus_DE	CANtouch_CAN bus-OK_Level_DE	CANtouch_CAN bus-OK_Oszi_DE	CANtouch_CAN-Bus-OK_Bus wiring_DE
Ok	CAN bus without error		Note I:Bus status: valid CAN telegrams available
	Can_h on Can_v+	no	CANtouch_CAN_L_short_Vcc_Busstatus_DE	CANtouch_CAN_H_short_CAN_V_absLevel_DE	Test setup without communication	CANtouch_CAN_H_short_CAN_V
	Can_h on Can_v+	Note V:Depending on the CAN transceiver type, some types can continue to communicate with this error Note VI:Depending on the amount of voltage and the duration of the action of the error (overheating of the CAN transceiver)	Note II:Bus status: static recessive		Note IV:Measurement without communication	Note III:Finds errors when supply voltages are measured with
	Can_l on Can_v+	no	CANtouch_CAN_L_short_Vcc_Busstatus_DE (1)	CANtouch_CAN_L_short_CAN_V_absLevel_DE	Test setup without communication	CANtouch_CAN_L_short_CAN_V
	Can_l on Can_v+	Note V:Depending on the CAN transceiver type, some types can continue to communicate with this error	Note II:Bus status: static recessive		Note IV:Measurement without communication	Note III:Finds errors when supply voltages are measured with
	Can_h on Vcc	Yes	CANtouch_CAN-Bus-OK_Busstatus_DE	CANtouch_CAN_H_short_Vcc_Level_DE	CANtouch_CAN_H_short_Vcc_Oszi_DE
	Can_h on Vcc		Note I:Bus status: valid CAN telegrams available		Note VII:Error in the difference signal not to recognize	Note VIII:A wiring test with connected participants is not recommended. It provides undefined errors whose statements are difficult to judge. The results displayed depend strongly on the interior circuit of the participants.
	Can_l on Vcc	no
	Can_l on Vcc		Note II:Bus status: static recessive		Note IV:Measurement without communication	Note VIII:A wiring test with connected participants is not recommended. It provides undefined errors whose statements are difficult to judge. The results displayed depend strongly on the interior circuit of the participants.
	Can_h on Can_v-	no
	Can_h on Can_v-		Note II:Bus status: static recessive		Note IV:Measurement without communication	Note III:Finds errors when supply voltages are measured with
	Can_l on Can_v-	Yes
	Can_l on Can_v-				Note VII:Error in the difference signal not to recognize	Note III:Finds errors when supply voltages are measured with
	Can_h on Can_l	no
	Can_h on Can_l		Note II:Bus status: static recessive		Note IV:Measurement without communication

Legend:

Vcc: Supply voltage of CAN transceiver

I) Bus status: valid CAN telegrams available

II) Bus status: static recessive

III) finds errors if supply voltages are measured with

IV) Measurement without communication

V) Depending on the CAN transceiver type, some types can continue to communicate with this error

VI) depending on the amount of voltage and the duration of the action of the error (overheating of the CAN transceiver)

VII) Error in the difference signal cannot be recognized

VIII) A wiring test with connected participants is not recommended.

It provides undefined errors whose statements are difficult to judge. The results displayed depend strongly on the interior circuit of the participants.