Diagnose fieldbus devices

Use a graduated approach to diagnosing fieldbus devices by first determining if the device is commissioned and then looking at overall port statistics and communication statistics for each device.

  1. Click View → Details or View → Compare to quickly see the device state. If the device is not commissioned, open the DeltaV Explorer and commission the device. If the device is commissioned, check integrity on the port and then check port and device communication statistics.

    Port Integrity

    Typically, integrity problems originate below the node and then "bubble up" to the node level. Integrity problems are indicated by the overlay. Start by looking for a controller with the overlay and if found, expand the controller hierarchy until you find the root cause of the problem. If a fieldbus card has an integrity problem, expand the card to see which port has the problem. Select each port and look at the port's status. Possible port status values are:

    • Good - good basic communications with all devices on this port.
    • No Termination on Link - this port is not terminated, check attached cable.
    • Link Error - PCMCIA Card problem, replace the H1 fieldbus card.
    • Duplicate Address on Link - another device is currently communicating at this port’s address.
    • No Communications on Link.
    • H1 Card Problem - replace the H1 fieldbus card.
    • One or more function block problems on link - expand the port and check the state of each fieldbus device on the port. Any state other then Commissioned indicates a potential problem with that fieldbus device.

    Communication Statistics

    The Port Statistics command provides a broad view of communication activity on the port. Right-click the port, and then select Display Port Statistics. In the Port Statistics dialog look for:

    • Invalid responses
    • Stack errors
    • Timeouts
    • Retries
    Note

    If any of the port statistics and communication statistics are continually increasing, a potential communications problem could exist on this port. To isolate the problem, investigate the communication statistics on each fieldbus device.

    Tip

    Clicking the Reset Stats button resets all values to 0 and makes it easier to read the statistics.

  2. Next, look at detailed port statistics. Right-click the port, and then select Display Port Detail Statistics. In the Detailed Port Statistics dialog look for:
    • Initiates
    • Aborts
    • Identifies
    • Aborts received and sent
    • Initiates received and sent
    • Pcr Timeouts
    • Livelist appearances - the number of times the device showed up as new
  3. Finally, look at communication statistics for each device. Right-click each device, select Display Communication Statistics, and look for:
    • Aborts received and sent
    • Initiates received and sent
    • Pcr Timeouts
    • Livelist appearances - the number of times the device showed up as new
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