Dynamic changes are advanced functions that allow us to change either the configuration of the PLC or the properties of the communication channels uploaded to the PLC. Therefore, it is not necessary to perform configuration directly in the IDE; individual configuration variables can be extracted, for example, to an HMI.

Using the functions described below, it is possible to program custom functional blocks in ST according to the project's requirements.

The function is used to write string values.

WriteResult := dynpar.setdynamicparamstr(id := ParamId, value := ParamToWrite);

• id: string_ref - parameter name
• value: string_ref - value of the parameter to write

• No output parameters

• 0 - no error
• -1 - record does not exist
• -2 - unknown requested type (cannot occur in practice)
• -3 - size mismatch between stored record and requested record (e.g., stored as bool and read as int)
• -4 - internal code error

The function is used to write integer values.

WriteResult := dynpar.setdynamicparamint(id := ParamId, value := ParamToWrite);

• id: string_ref - parameter name
• value: int - value of the parameter to write

• No output parameters

• 0 - no error
• -1 - record does not exist
• -2 - unknown requested type (cannot occur in practice)
• -3 - size mismatch between stored record and requested record (e.g., stored as bool and read as int)
• -4 - internal code error

The function is used to write boolean values.

WriteResult := dynpar.setdynamicparambool(id := ParamId, value := ParamToWrite);

• id: string_ref - parameter name
• value: bool - value of the parameter to write

• No output parameters

• 0 - no error
• -1 - record does not exist
• -2 - unknown requested type (cannot occur in practice)
• -3 - size mismatch between stored record and requested record (e.g., stored as bool and read as int)
• -4 - internal code error

The function is used to write time values.

WriteResult := dynpar.setdynamicparamtime(id := ParamId, value := ParamToWrite);

• id: string_ref - parameter name
• value: time - value of the parameter to write

• No output parameters

• 0 - no error
• -1 - record does not exist
• -2 - unknown requested type (cannot occur in practice)
• -3 - size mismatch between stored record and requested record (e.g., stored as bool and read as int)
• -4 - internal code error

The function is used to write date and time values.

WriteResult := dynpar.setdynamicparamdt(id := ParamId, value := ParamToWrite);

• id: string_ref - parameter name
• value: dt - value of the parameter to write

• No output parameters

• 0 - no error
• -1 - record does not exist
• -2 - unknown requested type (cannot occur in practice)
• -3 - size mismatch between stored record and requested record (e.g., stored as bool and read as int)
• -4 - internal code error

The function is used to read string values.

ReadResult := dynpar.trygetdynamicparamstr(id := ParamId, value => ReturnValue);

• id: string_ref - parameter name

• value: string - returned value of the parameter

• 0 - no error
• -1 - record does not exist
• -2 - unknown requested type (cannot occur in practice)
• -3 - size mismatch between stored record and requested record (e.g., stored as bool and read as int)
• -4 - internal code error

The function is used to read integer values.

ReadResult := dynpar.trygetdynamicparamint(id:= ParamId, value => ReturnValue);

• id: string_ref - parameter name

• value: int - returned value of the parameter

• 0 - no error
• -1 - record does not exist
• -2 - unknown requested type (cannot occur in practice)
• -3 - size mismatch between stored record and requested record (e.g., stored as bool and read as int)
• -4 - internal code error

The function is used to read boolean values.

ReadResult := dynpar.trygetdynamicparambool(id:= ParamId, value => ReturnValue);

• id: string_ref - parameter name

• value: bool - returned value of the parameter

• 0 - no error
• -1 - record does not exist
• -2 - unknown requested type (cannot occur in practice)
• -3 - size mismatch between stored record and requested record (e.g., stored as bool and read as int)
• -4 - internal code error

The function is used to read time values.

ReadResult := dynpar.trygetdynamicparamtime(id:= ParamId, value => ReturnValue);

• id: string_ref - parameter name

• value: time - returned value of the parameter

• 0 - no error
• -1 - record does not exist
• -2 - unknown requested type (cannot occur in practice)
• -3 - size mismatch between stored record and requested record (e.g., stored as bool and read as int)
• -4 - internal code error

The function is used to read date and time values.

ReadResult := dynpar.trygetdynamicparamdt(id:= ParamId, value => ReturnValue);

• id: string_ref - parameter name

• value: dt - returned value of the parameter

• 0 - no error
• -1 - record does not exist
• -2 - unknown requested type (cannot occur in practice)
• -3 - size mismatch between stored record and requested record (e.g., stored as bool and read as int)
• -4 - internal code error

The function is used to delete a dynamic parameter. Dynamic parameters can be deleted in bulk when uploading a configuration.

DeleteResult := dynpar.deletedynamicparam(ParamToDelete);

• id: string_ref - parameter name

• No output parameters

• 0 - no error
• -1 - record does not exist
• -2 - unknown requested type (cannot occur in practice)
• -3 - size mismatch between stored record and requested record (e.g., stored as bool and read as int)
• -4 - internal code error

The function is used to save the entire HW configuration tree to the PLC memory. It has no parameters.

CommitResult := dynpar.commithwconfiguration();

• 0 - no error
• -1 - record does not exist
• -2 - unknown requested type (cannot occur in practice)
• -3 - size mismatch between stored record and requested record (e.g., stored as bool and read as int)
• -4 - internal code error

The function is used to restart the PLC. You can specify the type of restart based on the given flag. If no flag is set, the PLC restarts in the standard way (Warm Restart).

RestartResult := reloadapplication(Flag);

Input Parameters - Flags (udint)

• 0x00 - Warm Restart
• 0x01 - Cold Restart
• 0x02 - Full system restart (reboot)

• No output parameters

• 0 - no error
• -1 - record does not exist
• -2 - unknown requested type (cannot occur in practice)
• -3 - size mismatch between stored record and requested record (e.g., stored as bool and read as int)
• -4 - internal code error

These keys can be found in the project directory in the bin directory, where there is a file with the .XML extension that can be opened in a text editor. This file is created by uploading the configuration to the PLC.

The prefix “hwcfg” is added before the keys for PLC configuration. In the XML file, we navigate through individual nodes, where for example, to set the PLC's IP address, we must write the key in the format “hwcfg.hwconfiguration.runtime.lwip.ipv4.@ipaddress”.

Keys for dynamic changes in image are listed in the “Output” tab in the format “OEM Key “channel>ComPort” → 9698843FC46A2D1A, datatype: SignedInteger32”, where “channel” is the channel name and “ComPort” is the parameter from which we want to read or write. The key is then followed by the data type of the parameter. In this case, we would use the function dynpar.trygetdynamicparamint for reading this key and dynpar.setdynamicparamint for writing.

For keys for changes in image, it is necessary to add the prefix “image” before the listed keys. For example, to change the communication port of a modbus serial channel named “modbus_channel”, the key should be written as “image.modbus_channel>ComPort”.