This feature makes it possible to control when an external item’s value shall be transferred
to another item. It may not always be the case that we want the value to be transferred regardless
of the value. Here we may select between different rules for when a transfer should be carried out
depending on the external item value. In addition we may set up the system such that the value is
transferred from different external items depending on the value of a third item (MUX).
The following item attributes must be specified:
Attribute ID
Name
Description
Type
5980
ExtTransferCtrlMethod
The control method that decides when external items are transferred to the item of the
attribute. One of the following may be selected:
Name
Meaning
Value
always
Always transfer external item values
0
when CtrlItem changes from zero
Transfer once when control item (ExtTransferCtrlItem) value changes from 0
1
when CtrlItem is zero
Transfer when control item (ExtTransferCtrlItem) value = 0
2
when CtrlItem is non zero
Transfer once when control item (ExtTransferCtrlItem) value is != 0
3
when CtrlItem becomes > argument
Transfer once when control item (ExtTransferCtrlItem) value becomes
greater than argument value (ExtTransferCtrlArgument)
10
when CtrlItem becomes < argument
Transfer once when control item (ExtTransferCtrlItem) value becomes
less than argument value (ExtTransferCtrlArgument)
11
when CtrlItem becomes = argument
Transfer once when control item (ExtTransferCtrlItem) value
becomes equal argument value (ExtTransferCtrlArgument)
12
when CtrlItem becomes <> argument
Transfer once when control item (ExtTransferCtrlItem) value becomes
different argument value (ExtTransferCtrlArgument)
13
when CtrlItem > argument
Transfer once when control item (ExtTransferCtrlItem) value is
greater than argument value (ExtTransferCtrlArgument)
20
when CtrlItem < argument
Transfer once when control item (ExtTransferCtrlItem) value
is less than argument value (ExtTransferCtrlArgument)
21
when CtrlItem = argument
Transfer once when control item (ExtTransferCtrlItem) value
is equal to argument value (ExtTransferCtrlArgument)
22
when CtrlItem <> argument
Transfer once when control item (ExtTransferCtrlItem) value is
different from argument value (ExtTransferCtrlArgument)
23
2 byte unsigned integer
5982
ExtTransferCtrlItem
The Item ID of another item, whose value will control the
transfer of external item values to this item
string
5984
ExtTransferCtrlArgument
The argument to use with the ExtTransferCtrlMethod
string
5986
ExtTransferCtrlInhibitQuality (Note that not all item-types will have this functionality implemented)
The quality to set when external item value transfer is inhibited, as a result of
the chosen ExtTransferCtrlMethod. When other than none, data is still transferred
during control method failure.
When none, data transfer stops during control method failure.
The attribute is enumerated, with the following options:
Name
Meaning
Value
none
Quality is not set/altered upon control method failure, but data transfer is inhibited
0
quality: bad
Quality is set to this value upon control method failure, but data is still transferred
65536
quality: uncertain
Quality is set to this value upon control method failure, but data is still transferred
65600
quality: good
Quality is set to this value upon control method failure, but data is still transferred
65728
quality: bad:config error
Quality is set to this value upon control method failure, but data is still transferred
65540
quality: bad:not connected
Quality is set to this value upon control method failure, but data is still transferred
65544
quality: bad:device failure
Quality is set to this value upon control method failure, but data is still transferred
65548
quality: bad:sensor failure
Quality is set to this value upon control method failure, but data is still transferred
65552
quality: bad:last known value
Quality is set to this value upon control method failure, but data is still transferred
65556
quality: bad:comm failure
Quality is set to this value upon control method failure, but data is still transferred
65560
quality: bad:out of service
Quality is set to this value upon control method failure, but data is still transferred
65564
quality: bad:waiting for initial data
Quality is set to this value upon control method failure, but data is still transferred
65568
quality: uncertain:last usable
Quality is set to this value upon control method failure, but data is still transferred
65604
quality: uncertain:sensor not accurate
Quality is set to this value upon control method failure, but data is still transferred
65616
quality: uncertain:engineering units exceeded
Quality is set to this value upon control method failure, but data is still transferred
65620
quality: uncertain:sub normal
Quality is set to this value upon control method failure, but data is still transferred
65624
quality: good:local override
Quality is set to this value upon control method failure, but data is still transferred
65752
4 byte unsigned integer
*** Note: *** The module property ExtItemCalculationSequence
is important in data validation and transfer. It decides whether data validation or data transfer
will be performed first in the external item manager.
Available values: TransferBeforeValidation, ValidationBeforeTransfer.
ExtItemOverrideMethod.
This attribute decides what method to use when assigning a value from an external item.
One of the following may be selected: “Default” or “Assign complete value from external item”.