User`s guide

26 • OPC Client Sample Program
Step 6. After groups have been added, you can select some items and
click Add Item button to add these items to a selected group.
Or you can click Add All Items button to add all items on the
server to a selected group.
Now we should take a look at the Items in Current Group list. There are
eight columns in the list, which are described as follows:
l Item Name: It is presented in the device.item format.
l Data Type: canonical data type
l Vaule: current data value
l R/W: access right
l Time Stamp: indicates the time when the item value is acquired.
l C/H: client handle. A handle defined in client to identify a specified
item.
l S/H: server handle. A handle defined in server to identify a
specified item.
l HRESULT: return error for each item when performing read/write.
Step 7. After adding items to a selected group, you can perform
read/write operation. Or you can build a connection point
between server and client. Hence there will be a callback
occurred when the item values change.