Technical Reference Manual - InduSoft

Communication with Other Devices
Area / Element
Description
Note: This is enabled by default. If it is disabled, then you must use read triggers (see
below).
Write actions
Maximum group size
Synchronous read
trigger
Asynchronous read
trigger
Read count
Status
Status message
Maximum aging
Enable write on tag
change
The maximum number of tag reads that may be performed in a single read operation.
For example, if you have 1000 items/rows configured in the worksheet and Maximum group size is set
to 100, then 10 read operations will be performed during each scan of the worksheet.
When the value of this tag/expression changes, the worksheet is scanned and all tag values are read
from the server. The project waits for the scan to complete before continuing.
When the value of this tag/expression changes, the worksheet is scanned and all tag values are read
from the server. The project continues running without waiting for the scan to complete.
The name of a tag (Integer type) that will receive a count of the number of read operations performed
since the project was run.
The name of a tag (Integer type) that will receive a status code for the last read operation performed by
a trigger.
The name of a tag (String type) that will receive the corresponding status message.
The maximum age (in milliseconds) of values that will be accepted from the server's cache. If a value is
older than this, then the server will be forced to get the latest value from the target device.
When this value is TRUE (non-zero), a write will be automatically performed whenever the value of the
project tag changes.
Note: This is enabled by default. If it is disabled, then you must use write triggers (see
below).
Reload trigger
Refresh IDs on startup
Maximum group size
Synchronous write
trigger
Asynchronous write
trigger
Write count
Status
Status message
The maximum number of tag writes to be performed in a single write operation.
For example, if you have 1000 items/rows configured in the worksheet and Maximum group size is set
to 100, then 10 write operations will be performed during each scan of the worksheet.
When the value of this tag/expression changes, the worksheet is scanned and all tag values are written
to the server. The project waits for the scan to complete before continuing.
When the value of this tag/expression changes, the worksheet is scanned and all tag values are written
to the server. The project continues running without waiting for the scan to complete.
The name of a tag (Integer type) that will receive a count of the number of write operations performed
since the project was run.
The name of a tag (Integer type) that will receive a status code for the last write operation performed by
a trigger.
The name of a tag (String type) that will receive the corresponding status message.
Indirect tags (e.g., {MyTag}) configured in the body of the worksheet will be reloaded only when the
value of this tag/expression changes.
When this option is selected, the node IDs in the worksheet will be refreshed from the specified item
paths every time the project is run.
Note: Refreshing IDs like this may cause the project to take longer to start up, so if you
select this option, then you should also specify a root node (see below) to limit how much
of the server's list of items must scanned.
Enable bit notation
When this option is selected, bit notation is allowed in the Item column of the worksheet body.
Note: IWS's OPC client does not normally use the Triggering Mode that is defined the OPC
protocol. Instead, it allows any change in any tag/expression to be used as a trigger. If you want
to use Triggering Mode, configure one worksheet to read the trigger values and then configure
another worksheet that specifies the read values as triggers.
5. Click OK to close the Advanced dialog and return to the worksheet.
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