Rockwell Automation 1757-PROCESSLINX ProcessLinx OPC Server to Server Software User Manual - Manual (Page 35)

Publication 1757-UM002B-EN-P - January 2003
ProcessLinx TagMap Configuration 3-15
Creating a ProcessLinx TagMap Configuration
Once you create the ProcessLogix and the External OPC Server configuration
a ProcessLinx configuration is created.
ProcessLogix Control Points defined within Control Builder can be browsed.
Other points such as Analog, Accumulator and Status Points cannot. To make
the ProcessLogix points browseable, select the desired control blocks from
Control Builder and select File
⇒
Export. This operation exports the
selected control blocks to UNICODE ASCII files which ProcessLinx parses
and compiles into a browseable list of function blocks for the Tag Maps dialog
box. ProcessLinx uses this compiled list of blocks in conjunction with an OPC
item file. The item file <ProcessLinx.itm> defines all the parameters or OPC
Items for each block type found in the compiled list of function blocks.
(This item file should be provided by Rockwell Automation and exists within
the same directory as the ProcessLinx executable.)
Data Type Data Type displays the default OPC tag type for the selected OPC
Item.
This is set to “native” initially. In runtime, the actual OPC Item’s
data type is received from the OPC Server and subsequently
displayed.
Access The OPC Item Access displays in this field.
This attribute is defined in the Parent Group and is read only.
“Read Only” indicates that no value can be written to the OPC
Item.
“Write Only” means the OPC Item is written to and not read.
Exception reported values from the OPC Server are
disregarded if the Item is Write Only.
“Read/Write” indicates the tag is both read from and written to.
In this case, the Data Master entry defines which OPC Server
initializes.
Automatically set
Mode Attribute Tag
(MODEATTR) to
PROGRAM state This ProcessLogix-Only selection allows proper mode conversion
between an External OPC Server and the ProcessLogix Server.
If the ProcessLogix OPC Item is a control element (such as an OP, SP
or MODE) that is written to from the External OPC Server, this must
be enabled.
In order for an external source to change the value of an OP, SP or
MODE element in ProcessLogix, it needs to set the MODEATTR tag
to PROGRAM state first and then write the value. Otherwise
ProcessLogix will reject the value. By setting this checkbox
ProcessLinx automatically sets the mode to “Program” and writes in
the new value. If the Server is not a ProcessLogix system, the
checkbox does not appear.
Table 3.C TagMap Data Attributes
Attribute Description