Inserting a field device - Metasys - LIT-12013150 - System Integration - Modbus Vendor Integration - 10.1 - 9.0.7

Network Engine Commissioning for Modbus Vendor Integration Application Note

Product name
Modbus Vendor Integration
Document type
Application Note
Document number
LIT-12013150
Version
10.1
9.0.7
Revision date
2021-03-03

Procedure

  1. Use the Launcher to log on to the network engine's SMP. If you need to install the Launcher, refer to Launcher Installation Instructions (LIT-12011783).
  2. Drag the Modbus integration object from the navigation panel to the display paneI. The Focus tab for the Modbus integration appears.
  3. Click Insert > Field Device . The Insert Field Device Wizard appears.
  4. In the Destination window, select Modbus Integration, and click Next.
  5. In the Select Definition Mode window, enter a field device definition in the Vendor Reference field, and click Next.
    Figure 1. Insert Field Device Wizard - Select Definition Mode

  6. In the Identifier window, enter a unique name for the device, and click Next.
    Figure 2. Insert Field Device Wizard - Identifier
  7. In the Configure window, click Next.
    Figure 3. Insert Field Device Wizard - Configure
  8. Click Finish to complete the Insert Field Device Wizard. The navigation panel refreshes to indicate the new field device.
  9. Drag the new field device object from the navigation panel to the display panel.
  10. Click the Hardware tab.
  11. Click Edit.
  12. Click the browse button in the Vendor Configuration Data field to open the Modify List dialog box. Figure 4 shows the default values for each communication mode.
    Figure 4. Field device parameters for a Modbus RTU device (left) and Modbus TCP device (right)

  13. Modify the parameters as necessary. Click OK to save the changes. See Table 1 for a list of parameter values. Also, refer to any support documentation that you might have received for your particular device integration.
    Table 1. Field device parameters

    Parameter

    Value

    [1]

    Represents the Modbus lower-level device address (1...247) in Modbus RTU mode, or the full Modbus lower-level device address in Modbus TCP mode. The full Modbus lower-level device address consists of the lower-level device address 1...247, followed by a <space> character, followed by the IP address of the device or gateway in IPv4 format (for example: 3 10.10.26.207).

    For Modbus TCP mode, the default port is 502. If a different port is used, you must specify it after the IP address (for example: 3 10.10.26.203:503).

    [2]

    When using Modbus communications, represents the response timeout in milliseconds. The timeout should be five to ten times the pacing in parameter [3] in this table. Initially, use 1000 ms for TCP and 2000 ms for RTU.

    [3]

    Represents the delay between polls in milliseconds. Initially, use 100 for TCP and 250 for RTU.

    [4]

    Represents the number of retries if there is no response.

    [5]

    Represents the maximum number of consecutive registers read for optimization. This number must be at least 2 if any of the data registers are read in floating-point format or DWord format, and it must be at least 4 if special 64-bit values are read.

    The following examples explain the use of parameters 5 and 6.

    Example 1: A power meter maps measurements from Modbus register 1 to Modbus register 30, the maximum registers to read is 125. The optimal configuration reads all 30 Modbus registers using a single request, so parameter 5 has a value of 30.

    However, if you map only measurements from registers 1 to 10, and 21 to 30, so there are 10 Modbus registers missing in the request. Parameter 6 can handle this gap. If parameter 6 is equal to 10, the driver reads the entire Registers block, even if registers 11 to 20 are not required.

    Example 2: A power meter maps measurements only from registers 1 to 10, and from 21 to 30. The driver cannot read unused registers. In this case, set parameter 5 to a value of 30, but set parameter 6 to 0. Because the gaps are not allowed, the driver handles the two requests in the following way:

    • The driver reads registers from 1 to 10.
    • The driver reads registers from 21 to 30.
    Note: If an errant operation occurs, set parameter [5] to 1 to read registers one by one.
    [6]

    Represents the maximum gap of registers acceptable for an optimized read (has to be less than parameter [5]).

    [7]

    Enables (when set to Y) or disables (when set to N) the use of Modbus write function 16. If set to N, Modbus write function 6 is used. If set to Y, Modbus write function 16 is used.

    Even if Modbus function 16 is not required, it is used automatically when trying to write a value that takes up or spans multiple registers (floating point or DWord values).

    [8]

    Represents the name of the resource file used for point discovery and Modbus data interpretation. The contents of this parameter must match exactly the file name in the Status section of the Configure window of the Insert Resource File wizard. See Figure 3. Use copy and paste between the two fields to minimize the possibility of error.

    The resource file name has the following structure:

    <Integration ID>.<VMD File Name>.vmd

    Example:

    ModbusRTU.ClimateMaster.vmd

    Note: The maximum length of the resource file name is 40 characters.
    [9]

    Represents Custom Address Parameter 1

    These parameters are used for address calculation formulas. Their values depend on the integration type. If they are required, you can find their descriptions in the application notes related to the specific devices. In all other cases, they have a value of 0.

    [10]

    Represents Custom Address Parameter 2

    [11]

    Represents Custom Address Parameter 3

    [12]

    Represents Custom Internal Parameter 1

    These parameters are used for internal calculation formulas. Their values depend on the integration type. If they are required, you can find their descriptions in the application notes related to the specific devices. In all other cases, they have a value of 0.

    [13]

    Represents Custom Internal Parameter 2

    [14]

    Represents Custom Internal Parameter 3

    [15]

    Has the same meaning as parameter 10 at the integration level. This parameter specifies whether the Permanent Polling strategy must be used for the device. In order to use permanent polling at the device level, set parameter 10 to N at the integration level.

    [16]

    Used to ignore exception codes sent by the field device. If this field is set to N (default), no exception codes are ignored. To specify the exception codes to ignore, list them in the parameter, separated by commas (for example: 10, 11 means ignore these codes). When an exception code is received from the device, the points remain at the previous value and previous status.
    Note: To ignore a gateway that has trouble responding within a certain number of milliseconds, specify exception codes 10,11.
  14. Click OK to close the Modify List dialog box. All changes made have been saved and the new parameters take effect.