Remember that the Diagnostics online help contains descriptions of all fieldbus parameter values. To access the descriptions, select the parameter, click the right mouse button, and select Help.
Use DeltaV Diagnostics to:
- Determine if the device is commissioned
- Check integrity on the H1 card, backup link master device, and ports
- Check overall port statistics and communication statistics for each device
Open DeltaV Diagnostics and click or to quickly see the device state. If the device is not commissioned, open the DeltaV Explorer and commission the device. Then, download the port and 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.
- Link Error: possible card problem. Reseat the H1 card to verify the card's self-test. If the problem persists, replace the H1 card, and notify Technical Support.
- Duplicate Address on Link: another device is currently communicating at this port's address.
- No Communications on Link.
- H1 Card Problem: Reseat the H1 card to verify the card's self-test. If the problem persists, replace the H1 card, and notify Technical Support.
- One or more function block problems on link or device problems: expand the port and check the state of each fieldbus device on the port. Any state other than Commissioned indicates a potential problem with that fieldbus device. Refer to the DeltaV Explorer help for assistance on commissioning fieldbus devices.
- A configuration error indicated by the device state "Device Class Mismatch": a backup link master is functioning as a basic device or a basic device is functioning as a link master device.
- A download error indicated by the device state "Schedule Download Failure": the Link Active Scheduler's (LAS) download of the schedule to this device failed
Port communication statistics
The Port Statistics command provides a broad view of communication activity on the port. Click the right mouse button on the port and select Port Statistics. In the Port Statistics dialog look for:
- Retries - Total Dll Retries is the total number of data link packets that the H1 card had to retry. If this statistic is steadily increasing, check the communication statistics for each device to see which device is causing the problem. To check communication statistics on a device, click the right mouse button on the device and select Display Communication Statistics. The number of retries to a fieldbus device generally should be much less then 1% of the total requests sent to the device. If this is not the case, either the device is bad or there is a segment problem.
- Invalid responses - Total Invalid Responses is the total number of fieldbus requests that failed due to a fieldbus device returning an error. If this statistic is steadily increasing, check the communication statistics for each device to see which device is causing the problem. To check communication statistics on a device, click the right mouse button on the device and select Display Communication Statistics.
- Stack errors - Total Local Stack Errors is the total number of fieldbus request that failed because the local communication stack returned a response that indicated an error. The H1 card might need to be replaced if this statistic is steadily increasing. Total Stack Rejected Request is the total number of fieldbus requests that failed because the local communication stack did not accept the request. The H1 card might need to be replaced if this statistic is steadily increasing.
- Timeouts - Total Request TimeOut is the total number of fieldbus request that failed because the fieldbus device did not return a response. If this statistic is steadily increasing, check the communication statistics for each device to see which device is causing the problem. To check communication statistics on a device, click the right mouse button on the device and select Display Communication Statistics.
Clicking the Reset Stats button resets all values to 0 and makes it easier to read the statistics. Click the Help button on any of the Port Statistics dialog boxes for information on the status values.
Next, look at detailed port statistics. Click the right mouse button on the port and select Display Port Detail Statistics. The FMS prefix in some of the detailed port statistics refers to the Fieldbus Message Specification services. These services allow user applications to send messages to each other across the fieldbus using a standard set of message formats. The SM prefix refers to System Management. System Management handles many functions on the fieldbus including automatically assigning fieldbus device addresses and searching for tags. In the Detailed Port Statistics dialog look for:
- Identifies - FMS Identifies is the number of fieldbus FMS (Fieldbus Message Service) identify requests that were sent on this port. SM Identifies is the number of fieldbus requests that were sent to identify a field device. This request is sent whenever a device has been attached to this port or changed addresses. If this statistic is incrementing after all field devices on this port have been commissioned, either a segment or a field device problem could exist. To isolate the problem, view the communication statistic on each field device on this port.
- Initiates - FMS Initiates is the number of fieldbus connection requests that were sent on this port. If this statistic steadily increments after all devices are commissioned and downloaded, either the fieldbus segment is noisy or a problem exists with a fieldbus device. To isolate the problem, check the communication statistics on each fieldbus device attached to this port. To check communication statistics on a device, click the right mouse button on the device, and select Display Communication Statistics.
- Aborts - FMS Aborts is the number of fieldbus disconnection requests that were sent on this port. If this statistic steadily increments after all devices have been commissioned and downloaded, there could be a problem with a fieldbus device or a noisy segment. To isolate the problem, check the communication statistics on each fieldbus device attached to this port. To check communication statistics on a device, click the right mouse button on the device, and select Display Communication Statistics.
Device communication statistics
Finally, look at communication statistics for each device. Click the right mouse button on each device, select Display Communication Statistics, and look for:
- Aborts received and sent - AbortsRxd is the total number of disconnects received from the function blocks in this device. If this statistic is steadily increasing for this field device only, the device could have a problem. If this statistic is steadily increasing with several field devices, a segment problem could exist. AbortsSent is the total number of disconnects sent to the function blocks in this device. If this statistic is steadily increasing with this field device only, the field device could have a problem. If this statistic is steadily increasing with several field devices, a segment problem could exist.
- Initiates received and sent - InitsSent is the total number of connects sent to the function blocks in this device. If this statistic is steadily increasing for this field device only, the field device could have a problem. If this statistic is steadily increasing for several field devices, a segment problem could exist.
- Pcr Timeouts - PcrTimeoutsRxd is the total number of fieldbus requests sent to the function blocks that failed because the field device did not return a response. The device might have a problem, if this statistic is steadily increasing.
- Livelist appearances - NumLiveListAppearances is the number of times the device left the segment and was brought back online. If this statistic is incrementing, there is either a problem with this device, or a segment problem.