Controller Boot Failure or EtherCAT Communication Error

Error [1.4026] is a general message. It usually indicates one of two situations:

• The controller does not boot. The teach pendant shows nothing, or stops partway through booting.
• The controller boots, but communication with the robot arm fails. The robot cannot be driven, and a connection error may be shown.

[1.4026] Framework category

An error situation occurred.
Param 1: Error code

The controller and the joints of the robot arm talk to each other over a communication network called EtherCAT. When that communication fails, the robot raises 1.4026 (or 1.4025) or shows a connection error. Write down the Param 1 value — it tells support what failed.

• Communication cable — the most frequent. A bent pin in the robot arm cable connector, or a loose cable.
• Improper power-off — switching off the controller while the robot is running, or a sudden power outage, is the most common reason a controller stops booting.
• Program overloading the controller — a while, repeat or thread block that runs with no wait keeps the controller busy, and communication frames are dropped.
• A part in the controller or the robot arm — this needs service.

• Turn the robot off properly from the teach pendant, wait, and turn it on again. In future, always shut down from the teach pendant before switching off the power.
• With the power off, disconnect the robot arm cable at the controller and look closely at the connector for bent or damaged pins. Reconnect it firmly.
• Check the arm cable along its length for damage or sharp bends.
• If the error appears while a program is running, check every while, repeat and thread loop in the program. Add a short wait inside any loop that runs with no delay.
• If a "Data Access Error" message also appears repeatedly, check that the program data is arranged as the user manual and programming manual describe.
• Note whether the error happens at boot, at servo on, or during a program.

If the controller still does not boot, or the error continues, contact your distributor. Do not open the controller.

• Robot model and serial number
• Software version of the controller
• The Param 1 value, all codes shown with 1.4026, and the date and time
• Whether the controller boots, and what the teach pendant shows
• Whether there was a power outage or improper power-off
• The controller log, if the controller boots

• 1.4025 Async Cycle frame transmission failed
• 4.1023 Communication Error-Heart Beat
• 5.7021 Raw data sequence number error occurred on Inverter board
• 5.7023 Joint torque sensor data sequence number error occurred on Inverter board
• 5.7025 Motion Controller data sequence number error occurred