Block writes let you send data to various registers in the OPC server simultaneously by using a special "send" command. This command instructs the OPC Client to send all outstanding writes in a single protocol message.
When the OPC Client sends the array to the OPC server, it also sends any unmodified values in the array using the last known value. Consequently, reads from the array return old values until the new data is written.
To send block writes through
iFIX:
- Enable block writes in the OPC item you want to use:
- In the Tree Browser, select the OPC item you want to use.
- In the Properties Viewer, select the Enable Block Writes check box.
- Create a Digital Output block with the following address:
Note that only item names are valid with the !Send control address. You cannot trigger block names using the following items:
- Server and group names in place of an item name.
- Analog Output blocks in place of a Digital Output block.
