Read controller tags – Rockwell Automation 1768-EWEB EtherNet/IP Web Server Module User Manual User Manual

Page 94

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Publication ENET-UM527E-EN-P - October 2006

94 Create Custom Web Pages

Read Controller Tags

There are two ASP functions you can use to read controller tags:

Function:

ReadLogixTag(path, tagname, tagtype)

The

ReadLogixTag

function connects to a controller at a specified

path

, retrieves the value of a tag with a name

tagname

and of

tagtype

.

Parameters:

Example:

For example, retrieve a DINT tag named ’my_dint_tag’ from a
controller in slot 3 of the local chassis:

<p> "my_dint_tag" value:

<% ReadLogixTag("1,3", "my_dint_tag", "DINT"); %>

</p>

Function:

ReadLogixTagUnconnected(path, tagname, tagtype)

The

ReadLogixTagUnconnected

function performs the same task as

ReadLogixTag

function and uses the same parameters. This function,

however, retrieves the tag value through unconnected messaging,
rather than connected messaging.

If You Want

Use This ASP Function

See Page

Connected messaging

ReadLogixTag

94

Unconnected messaging

ReadLogixTagUnconnected

94

Parameter

Description

path

The path is a CIP path, with no spaces, and segments separated by commas. For example:

tagname

The tagname identifies a controller-scoped tag.

tagtype

The tagtype must be an atomic type (BOOL, SINT, INT, DINT, REAL) or string. Use standard
dot notation to specify a member of an array or a user-defined structure (for example,
’timer1.ACC’ for the accumulator of a timer tag named ’timer1’).

Path Example

Description

1,3

1 = backplane
3 = slot 3

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