The DeltaV Explorer, Control Studio, and Diagnostics programs as well as the H1 card itself provide a great deal of diagnostic information on fieldbus devices.
H1 fieldbus Card
Communication information between the card and fieldbus devices is available from a visual inspection of the H1 card. The bottom two LEDs on the H1 card reflect communication between the port and fieldbus devices on that port. A blinking yellow LED indicates that the port is communicating with fieldbus devices but either a communication problem exists with an attached fieldbus device or no function blocks are configured on the segment. If the LED is off, either the port is disabled or the H1 card is not communicating with any fieldbus devices on the port. Use the DeltaV Explorer to enable and download the port and Control Studio to create and download configuration. A solid yellow LED indicates good communication between the port and devices on that port and at least one function block is configured on the segment.
DeltaV Explorer
Indicators in the DeltaV Explorer tell you if an H1 port or a fieldbus device needs to be downloaded or commissioned.
The
on an H1 port or device means that the port or device needs to be downloaded. Right-click the port or device, and then select Download to open a dialog that lists the fieldbus configuration information to be downloaded.The
on a device means that the device needs to be commissioned. To commission the device, select it from the Decommissioned device list and drag it to either the port or device placeholder.
Control Studio
Use Control Studio in online mode to diagnose problems with modules running in fieldbus devices. You must assign and download a module before viewing it in online mode.
- Click to create an online (or debug) session in which you can examine module and block parameters. A red X on a function block parameter indicates a problem with the function block.
CAUTION!Any online changes affect your process because the changes are made to downloaded modules in the controller. Use extreme care when changing values or stopping the execution of an algorithm.
Diagnostics
Use DeltaV Diagnostics to perform the following tasks:
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 rise 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 exists. Replace the H1 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 card.
One or more function block problems on link or device problem - 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.
Port Communication Statistics
The Port Statistics command provides a broad view of communication activity on the port. Right-click the port, and then select Port Statistics. In the Port Statistics dialog, look for the following:
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. Refer to the following section for information.
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 the following:
Clicking the Reset Stats button resets all values to 0 and makes it easier to read the statistics.
Device Communication Statistics
Finally, look at communication statistics for each device. Rght-click each device, select Display Communication Statistics, and look for the following: