Alias Parameter

The protocols ASCII Setting COMx - ASCII and MODBUS Setting COMx - MODBUS work with function blocks which require the target COM port number as an input. The COM port number of the remote controlled port is an internal identifier and might differ because it depends on the existing remote COM interfaces of the project. To address a remote COM interface the parameter Alias which represents the corresponding COM interface is used:

Parameter	Default	Value	Meaning
Alias	‘COM_[x]_[y]’	STRING(80)	The alias of the COM port which represents the unique identifier of the COM port. By default the alias is generated by Automation Builder and consists of the slot number of the Communication Module (x) and the COM port’s index at the Communication Module (y).

Caution

It must be ensured that the alias string represents an IEC-conform variable name. Otherwise it will not be possible to compile the IEC project.

Automation_Builder automatically adds a new section RemoteInterface to the Global Variables of IEC 61131-3 editor V2.3.9.x project after (re)creating the configuration data. This section contains the generated aliases as constant variables which can be used to address each remote COM interface at the existing function blocks of the protocols (COM_SEND, COM_REC, COM_MOD_MAST).