A cold start is performed by switching power OFF/ON if no battery is connected.

All RAM memory modules are checked and erased .

If no user program is stored in the flash EPROM, the default values (as set on delivery) are applied to the interfaces.

If there is a user program stored in the flash EPROM, it is loaded into RAM.

The default operating modes set by the PLC configuration are applied.

A warm start is performed by switching power OFF/ON with a battery connected.

All RAM memory modules are checked and erased except of the buffered operand areas and the RETAIN variables .

If there is a user program stored in the flash EPROM, it is loaded into RAM.

The default operating modes set by the PLC configuration are applied.

By booting the CPU the connected IO modules are re-initialized and parameterized, therefore the IO output fails for a short time.

RUN -> STOP means pressing the RUN function key on the PLC while the PLC is in run mode (AC500 PLC display “run”, AC500-eCo PLC "RUN LED" is ON).

If a user program is loaded into RAM, execution is stopped.

The behavior of outputs in stop state is configurable. Double click on PLC_AC500_V3 in the project tree. In the “PLC_AC500_V3” tab click on “PLC Settings”.

• To activate update of I/O while in stop state, click the checkbox left of “Update I/O while in stop”.

• To specify the behavior of the outputs in stop state, select an option in the pull down menu right of “Behavior for outputs in stop”. Options are:

  “Keep current values”

  “Set all outputs to default”

  “Execute program” (If the “Execute program” option is selected, the “Input Assistant” must be opened via the [...] button and a program must be selected which is executed exactly once.)

Variables keep their current values, i.e., they are not initialized.

The AC500 PLC display changes from “run” to “StoP”, AC500-eCo "RUN LED" changes from ON to OFF.

START -> STOP means stopping the execution of the user program in the PLC's RAM using the menu item "Online/Stop" in the programming system.

The behavior of the outputs in stop state is configurable. Double click on PLC_AC500_V3 in the project tree. In the “PLC_AC500_V3” tab click on “PLC Settings”.

• To activate update of I/O while in stop state, click the checkbox left of “Update I/O while in stop”.

• To specify the behavior of the outputs in stop state, select an option in the pull down menu right of “Behavior for outputs in stop”. Options are:

  “Keep current values”

  “Set all outputs to default”

  “Execute program” (If the “Execute program” option is selected, the “Input Assistant” must be opened via the [...] button and a program must be selected which is executed exactly once.)

Variables keep their current values, i.e., they are not initialized.

The AC500 PLC display changes from “run” to “StoP”.

Performs a START -> STOP process.

Preparation for program restart, i.e., the variables (VAR) (exception: RETAIN variables) are set to their initialization values.

Reset is performed using the menu item "Online/Reset" in the programming system or pressing the function key RUN for ≥ 5 s in STOP mode.

Performs a START -> STOP process.

Preparation for program restart, i.e., the variables (VAR) (also RETAIN variables) are set to their initialization values.

Reset (cold) is performed using the menu item "Online/Reset (cold)" in the programming system.

Resets the controller to its original state (deletion of flash, SRAM (%M, area, %R area, RETAIN, RETAIN PERSISTENT), Communication Module configurations and user program!).

Reset (original) is performed using the menu item "Online/Reset (original)" in the programming system.

STOP -> RUN means short pressing the RUN function key on the PLC while the PLC is in STOP mode (AC500 PLC display "StoP", AC500-eCo "RUN LED" is ON). "RUN LED" is OFF of the toggle switch of an AC500-eCo CPU.

If a user program is loaded into RAM, execution is continued, i.e., variables will not be set to their initialization values.

The AC500 PLC display changes from "StoP" to "run", AC500-eCo "RUN LED" changes from OFF to ON.

STOP -> START means continuing the execution of the user program in the PLC's RAM using the menu item "Online/Start" in the programming system.

If a user program is loaded into RAM, execution is continued, i.e., variables will not be set to their initialization values.

The AC500 PLC display changes from "StoP" to "run", AC500-eCo PLC "RUN LED" changes from OFF to ON.

Download means loading the complete user program into the PLC's RAM. This process is started by selecting the menu item "Online/Download" in the programming system or after confirming a corresponding system message when switching to online mode (menu item "Online/Login").

Execution of the user program is stopped.

In order to store the user program to the user flash memory, the menu item "Online/Create boot project" must be called after downloading the program.

Variables are set to their initialization values according to the initialization table.

RETAIN variables can have wrong values as they can be allocated to other memory addresses in the new project!

A download is forced by the following:

• changed PLC configuration

• changed task configuration

• changed library management

• changed compile-specific settings (segment sizes)

• execution of the commands "Project/Clean all" and "Project/Rebuild All".

After a project has changed, only these changes are compiled when pressing the key <F11> or calling the menu item "Project/Build". The changed program parts are marked with a blue arrow in the block list.

The term Online Change means loading the changes made in the user program into the PLC's RAM using the programming system (after confirming a corresponding system message when switching to online mode, menu item "Online/Login").

Execution of the user program is not stopped. After downloading the program changes, the program is re-organized. During re-organization, no further online change command is allowed. The storage of the user program to the user flash memory using the command "Online/Create boot project" cannot be initiated until re-organization is completed.

Online Change is not possible after:

• changes in the PLC configuration

• changes in the task configuration

• changes in the library management

• changed compile-specific settings (segment sizes)

• performing the commands "Project/Clean all" and "Project/Rebuild All".

Data buffering, i.e., maintaining data after power ON/OFF, is only possible, if a battery is connected for AC500 CPU and the buffering will take place in the flash disk with AC500-eCo CPU. The following data can be buffered completely or in parts:

• Data in the addressable flag area (%M area)

• RETAIN variable

• PERSISTENT variable (number is limited, no structured variables)

• PERSISTENT area (%R area)

In order to buffer particular data, the data must be excluded from the initialization process ⮫ “Handling of remanent variables”.