CPU Overload (E23)

If the Motion Engine or PLC "Programmable Logic Controller" A Programmable Logic Controller, PLC, or Programmable Controller is a digital computer used for automation of industrial processes, such as control of machinery on factory assembly lines. Used to synchronize the flow of inputs from (physical) sensors and events with the flow of outputs to actuators and events program execution (VM) do not complete a full cycle within their respective timeout periods, an E23 error will be flashed on the 7-segment display.

Process	Timeout
Motion Engine	200 milliseconds
PLC Program (VM)	10 seconds

The Real-Time operation for EtherCAT ***EtherCAT is an open, high-performance Ethernet-based fieldbus system. The development goal of EtherCAT was to apply Ethernet to automation applications which require short data update times (also called cycle times) with low communication jitter (for synchronization purposes) and low hardware costs and the Motion Engine have the highest priority in the controller. The PLC Program (VM) has the second highest priority in the controller. These processes will continue to execute, even if their timeout values are exceeded.

If the CPU overload is severe, there may not be enough CPU time to execute the background operations. The background operations include the 7-Segment display update, monitoring push-buttons, web-server, Modbus ModBus is a serial communications protocol and is now the most commonly available means of connecting industrial electronic devices. ModBus is often used to connect a supervisory computer with a remote terminal unit in supervisory control and data acquisition (SCADA) systems. Versions of the ModBus protocol exist for serial port and Ethernet (it is widely used with TCP/IP over Ethernet), and communications with the KAS IDE "Integrated development environment" An integrated development environment is a type of computer software that assists computer programmers in developing software. IDEs normally consist of a source code editor, a compiler and/or interpreter, build-automation tools, and a debugger. The 7-Segment will indicate a CPU overload or frozen software task by displaying one of the following patterns:

Display	Meaning
	CPU overload is extreme.
	Motion thread is no longer able to execute.
	EtherCAT Rx thread is no longer able to execute.
	PLC thread is no longer able to execute.
	Non-realtime threads are no longer able to execute.

To recover from an E23, stop the application from the IDE or web-browser (KAS Application view). If the CPU overload is severe, the controller may not have enough CPU time to respond to the IDE or web-browser. In this case, you will need to power-off/on the controller. If the PCMM or AKD PDMM is configured for Auto-start, press and hold the B3 menu button at boot-time to prevent the application from automatically re-starting. Then, you will be able to connect to the Controller with the IDE.