Add a Tag in OPC Tag Database Manager

Tags from different sources can be added within the OPC Tag Database Manager. They must be added here before they can be accessed in Runtime. The tags are formatted into the standardized OPC format for integration with industrial automation and control systems.

To add a tag to OPC Tag Database Manager, follow the steps below.

  1. Click Add.
  2. In the General pane, fill in the below values.
    Name The Name of the OPC tag to add.
    Type The tag type for the OPC tag. Choose from:
    • Modbus — Connect to a Modbus-enabled PLC device.
    • Omron FINS Ethernet — Connect to an Omron-enabled PLC device.
    • OPCDA Source — Connect to an OPC Data Access Server tag.
    • Virtual — Create simulated values which are not tied to any tag database or server. The tags created are local to the Tag Database Manager. This type is primarily used for testing.
  3. Fill in the Advanced Settings for the selected tag type.
    Table 1. Modbus
    Network Address The address of the device on the network you wish to connect to.
    Port The port used for the connection to the OPC device.
    Slave Address The address for the specific slave device to be connected to.
    Address The location/register number for where the tag is located.
    Data Type The data type of the tag being added. Options are:
    • Word
    • Word Array
    • Boolean
    • Boolean Array
    Array Size The length of the array. This is only available for the Word Array and Boolean Array data types.
    Note: For word arrays, the maximum array size is 120. For boolean arrays, the limit is 1968.
    Scan Rate (msec) The rate in millisecond at which the tag is scanned for its state.
    Note: Modbus includes a Write-Only option if the scanning rate is set to 0ms.
    Table 2. Omron FINS Ethernet
    Network Address The address of the device on the network you wish to connect to.
    Port The port used for the connection to the OPC device.
    Source Network Address Number Specifies the address number of the source network. The valid range is 0 to 127.
    Source Node Number Specifies the number of the source node. The valid range is 0 to 254.
    Note: Setting the source node number to 0 automatically assigns the node number of the Omron device based on the 4th octet of its own IP address.
    Destination Network Address Number Specifies the address number of the destination device. The valid range is 0 to 127.
    Destination Node Number Specifies the node number of the destination device. The valid range is 0 to 254.
    Note: When a Destination Node Number of 0 is entered, it will take the 4th octet of the target IP address.
    Destination Unit Number Specifies the number of the destination device unit number. The valid range is 0 to 255.
    Tag Address The address for the OPC tag being accessed on the device. To use the entire word value, enter only the address for the tag. To listen to a specific bit, place a period between the tag address and the bit number. E.g., to listen to bit 7 on tag D100, you would enter D100.7. To create a tag array, place square brackets with the array length between them. E.g., to listen to an array starting at tag D100 with a length of 10, you would enter D100[10]. The tag types supported are:
    • CIO (Computation Input/Output)
    • A (Auxiliary Relay)
    • D (Data Memory)
    • H (Holding Relay)
    • W (Work Memory)
    • E (Extended Memory)
    Note: When using an extended memory address, you must enter the specific memory bank being accessed (banks 0 to 24 are supported) after the category, and separate it from the rest of the address using a colon. For example, if you want to access the extended memory bank 3 for address 100, the address would be formatted as E03:100. The other formatting for arrays and accessing specific bits remains the same as other address types.
    Scan Rate (msec) The rate in millisecond at which the tag is scanned for its state.
    Note: The scan rate must be set to zero for it to be a Write-only tag.
    Table 3. OPCDA Source
    Machine Name The machine/computer where the tag database is located. To view a list of machines to connect to, click Browse Machines. The default is localhost.
    Server Class The OPC server on the selected machine. A machine can have multiple OPC servers. To view a list of servers to connect to, click Browse Available Servers.
    Item ID The item from the select server corresponding with this tag. To view items, click Browser Items.
    Update Interval The time interval in milliseconds between each update of the tag values from the server.
    Table 4. Virtual
    Data Type The type of data the tag will used. This can be:
    • Boolean
    • Int
    • String
    Array Check this box if your tag will contain multiple values.
    Length If the Array option is checked, enter in the number of values to be stored in this array.
    Randomize Check this box to have the tag continually updated with random values.
    Note: To view these updates, Live Tag Updates must be enabled in the Tag Display menu.
    Update Interval If Randomize is checked, this is the time interval in milliseconds between each update for the tag value.
    Max Limit If Randomize is selected and the Data Type is Int, this is the maximum possible value the tag can have.
    Min Limit If Randomize is selected and the Data Type is Int, this is the minimum possible value the tag can have.
  4. Click OK.