Referencing Cpu Variables With An Enum Type - Siemens SIMATIC S7-1200 System Manual

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Referencing CPU variables with an enum type

You can assign a variable in the CPU to an enum type. This variable can be used elsewhere

in your user-defined Web page in a read operation (Page 1044) or a write operation

(Page 1045). On a read operation, the Web server will replace the numerical value that is

read from the CPU with the corresponding enum text value. On a write operation, the Web

server will replace the text value with the integer value of the enumeration that corresponds

to the text before writing the value to the CPU.

The scope of an enum type reference is the current fragment.

Example usage in a variable read

...

<p>The current value of "Alarm" is :="Alarm":</p>

If the value of "Alarm" in the CPU is 2, the HTML page displays 'The current value of "Alarm"

is Tank is empty' because the enum type definition (Page 1050) assigns the text string "Tank

is empty" to the numerical value 2.

Example usage in a variable write

<!-- AWP_Enum_Def Name='AlarmEnum' Values='0:"No alarms", 1:"Tank is

full", 2:"Tank is empty"' -->

...

Because the enum type definition (Page 1050) assigns "Tank is full" to the numerical value

1, the value 1 is written to the PLC tag named "Alarm" in the CPU.

Note that the Enum clause in the AWP_In_Variable declaration must correspond exactly to

the Name clause in the AWP_Enum_Def declaration.

S7-1200 Programmable controller

System Manual, V4.2, 09/2016, A5E02486680-AK

Name of PLC tag or data block tag to associate with the enum type, or the name of

the alias name for a PLC tag (Page 1049) if declared.

Varname must be enclosed in single quotation marks. Within the single quotes, use

double quotation marks around a PLC tag or data block name. Note that for data

block tags, you use the name of the block and not a data block number. The data

block name is within the double quotes but not the data block tag name.

Name of the enumerated type, which must be enclosed in single or double quota-

12.7 User-defined Web pages