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write

(To be removed) Write values to group or items

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Support for the OPC Data Access (DA) standard will be removed in a future release. Instead use OPC Unified Architecture (UA). See Version History.

Syntax

write(GObj,Values)
write(IObj,Values)

Description

write(GObj,Values) writes values to all the items contained in the dagroup object GObj. Values is a cell array of values--one for each item. To ensure that a specific value is written to the correct item object, you should construct the Values cell array based on the order of the items returned by the Item property of GObj.

write(IObj,Values) writes values to all the items contained in the vector of daitem objects specified by IObj.

The data types of the values do not need to match the canonical data type of the associated items. However an error is returned if a data type conversion cannot be performed.

Because the values are written to the device, this operation might be slow. The function does not return until it verifies that the device has actually accepted or rejected the data.

Note

The behavior of an OPC server when writing NaN to an item is server-dependent. If you attempt to write NaN to an OPC server, the value might be silently ignored by the OPC server. That is, the server might not generate any events in response to writing NaN to an item.

example

Examples

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Configure a client, group, and items for the Matrikon™ Simulation Server.

da = opcda('localhost','Matrikon.OPC.Simulation');
connect(da);
grp = addgroup(da,'ExWrite');
itm = additem(grp,{'Bucket Brigade.Real8', ...
    'Bucket Brigade.String'});

Write and read values to and from the items.

write(grp,{23,'Hello World!'})
r1 = read(grp);
write(itm(1),15)
r2 = read(itm(1));

Input Arguments

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OPC DA group, specified as a dagroup object.

Example: addgroup()

OPC DA items, specified as an array of daitem objects.

Example: additem()

Data values, specified as a cell array.

Example: {23,'Label4'}

Data Types: cell

Version History

Introduced before R2006a

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See Also

Functions