Open Platform Communications (OPC) protocol configuration
- Last UpdatedApr 24, 2025
- 3 minute read
Open Platform Communications (OPC) protocol-specific fields can be configured in the Connection, Analog, Status, Rate and Remote Row Edit dialog boxes.
The following tables list the protocol-specific fields in different row edit dialog boxes. The appropriate entries are also described. For more information on these fields, refer to RealTime tables.
OPC protocol-specific fields on the Scan Edit tab in the connection Row Edit dialog
|
Field |
Input Description |
|---|---|
|
Comm. Mode |
Select Remote Poll. |
|
No communication timeout (sec) |
Set this to a small value greater than 0 (for example, 5 seconds). |
|
Maximum Time to Connect (sec) |
Set this to a small value (for example, 5 seconds). |
OPC protocol-specific fields on the Physical Connection Edit tab in the connection Row Edit dialog
|
Field |
Input Description |
|---|---|
|
Term. Server/Host Name |
Enter the name of the computer host where the OPC client process runs. |
|
Port Number |
Enter the OPC client’s listen port number. Refer to Open Platform Communications (OPC) client process for more information. |
OPC protocol-specific fields on the Input tab in the analog Row Edit dialog
|
Field |
Input Description |
|---|---|
|
Point Type |
Select an OPC-supported data type. Refer to Data types for more information. |
|
Input Coordinates |
Enter the group number and item name in the following format: groupnumber:itemname. Refer to Input/Output coordinates for Open Platform Communications (OPC) for more information. |
OPC protocol-specific fields on the Output tab in the analog Row Edit dialog
|
Field |
Input Description |
|---|---|
|
Output Type |
Select an OPC-supported data type. Refer to Data types for more information. |
|
Output Coordinates |
Enter the group number and item name in the following format: groupnumber:itemname. Refer to Input/Output coordinates for Open Platform Communications (OPC) for more information. |
OPC protocol-specific fields on the Input tab in the status Row Edit dialog
|
Field |
Input Description |
|---|---|
|
Number of Input Bits |
Enter 1 or 2. |
|
Coordinates |
Enter the group number and item name in the following format: groupnumber:itemname. Refer to Input/Output coordinates for Open Platform Communications (OPC) for more information. |
|
Bit Number |
Enter the bit number or bit position of the return value. Refer to the examples below. Note: To support bit-pack, return values for status points are 32-bit unsigned integers. |
Example 1
Item RTU.1 is configured on the OPC server as a boolean value, but returns as a 32-bit unsigned integer (0x00000000 for False or Ox00000001 for True). Bit number is 0.
Example 2
Item RTU.1 is configured on the OPC server as a 16-bit register, but returns as a 32-bit unsigned integer (0x0000XXXX where X is a used bit). Bit number a value from 0 to 15 to access the specific bit.
OPC protocol-specific fields on the Output tab in the status Row Edit dialog
|
Field |
Input Description |
|---|---|
|
Output Type |
Select Latched. OPC Client protocol only supports Latched. |
|
Coordinates |
Enter the group number and item name in the following format: groupnumber:itemname. Refer to Input/Output coordinates for Open Platform Communications (OPC) for more information. |
OPC protocol-specific fields on the Input tab in the rate Row Edit dialog (Pulse Input section)
|
Field |
Input Description |
|---|---|
|
Input Coordinates |
Enter the group number and item name in the following format: groupnumber:itemname. Refer to Input/Output coordinates for Open Platform Communications (OPC) for more information. |
|
Point Type |
Select an OPC-supported data type. Refer to Data types for more information. |
OPC protocol-specific fields on the Input tab in the rate Row Edit dialog (Analog Input section)
|
Field |
Input Description |
|---|---|
|
Input Coordinates |
Enter the group number and item name in the following format: groupnumber:itemname. Refer to Input/Output coordinates for Open Platform Communications (OPC) for more information. |
|
Point Type |
Select an OPC-supported data type. Refer to Data types for more information. |
OPC protocol-specific fields on the Main tab in the remote Row Edit dialog
|
Field |
Input Description |
|
Protocol |
Select OPC Client. |
Note: Many connections to the OPC client may be configured, but only one remote record may be associated to a connection.
OPC protocol-specific fields on the Scan Parameters tab in the remote Row Edit dialog
|
Field |
Input Description |
|---|---|
|
RTU Turnaround Time(ms) |
Set the time (in milliseconds). |
|
Overhead Processing Time (ms) |
This field is set depending on the maximum number of items in a group.This applies to INITITEMS commands. Refer to Open Platform Communications (OPC) special commands for more information. |
OPC protocol-specific fields in the Remote-Connection (Remconnjoin) table
|
Field |
Input Description |
|
Bad Test Frequency (min) |
How often you want to test a bad OPC Server. If the OPC Server is not available (down or disconnected), then you can periodically check its status in order to reconnect automatically when the OPC Server is available again. |