When you set an OPC data source for an object, you must specify the following:
The fully-qualified OPC item name for the data item you select. You may need to edit this field if you are accessing a data array or if the name is incorrect for some other reason. For the exact data array syntax your OPC server requires, consult your server's documentation.
The columns you want to display. By default, the VALUE is used. However, you can also display the quality and the timestamp of the OPC item.
NOTE: Some VARIANT types (for example, the Matrikon OPC Simulation data types 'Money' and 'Time') are not supported for use in Proficy Portal.
Bad data may be returned differently depending on the specific behavior of the OPC server. It is possible for an OPC server to report a value of zero when the data quality is bad because of a communication failure with the hardware device. When this occurs, you will see the following results in Proficy Portal:
|
Object Type |
Displays bad data as... |
|
Datalink |
0 |
|
Grid |
0 with a red box to indicate bad quality |
|
Combo Box |
No value |
|
List Box |
No value |
OPC data sources can be written to with objects such as datalinks and grids. The following exceptions apply:
The Array type cannot be written to.
Items can be written to only if the VALUE field is selected as the first field. For example, the fields VALUE, QUALITY, and TIMESTAMP may all be selected to appear, but VALUE must come first in order to write to the source.
