Connection issues

Check connectivity

Perform the following steps to verify active connections to the data source and egress endpoints.

1. Start PI Web API and verify that the PI point values are updating or start CONNECT data services and verify that the stream values are updating.

2. If configured, use a health endpoint to determine the status of the adapter. For more information, see Health and Diagnostics.

Adapter connection to egress endpoint

Certain egress health information in both PI Web API and CONNECT data services show if an adapter connection to an egress endpoint exists.

To verify an active connection, perform one of the following procedures:

PI Web API connection

Perform the following steps to determine if a connection to the PI Web API endpoint exists:

1. Open PI Web API.

2. Select the OmfEgress component of your adapter, for example GVAdapterUbuntu.Modbus TCP.OmfEgress.

3. Make sure that the following PI points have been created for your egress endpoint:

• DeviceStatus

• NextHealthMessageExpected

• IORate

CONNECT data services connection

Perform the following steps to determine if a connection to the CONNECT data services endpoint exists:

1. Open CONNECT data services.

2. Select Sequential Data Store > Streams.

3. Makes sure that the following streams have been created for your egress endpoint:

• DeviceStatus

• NextHealthMessageExpected

• IORate

TCP connection

Perform the following steps to see all established TCP sessions in Linux:

1. Open a terminal.

2. Type the following command: ss -o state established -t -p

3. Press Enter.

TCP Connection Exceptions

In very rare scenarios, the network or Modbus server may transmit a malformed packet causing the adapter to get into an unrecoverable state. If this happens, the debug logging will report an IOError exception followed by NoConnection exceptions. This happens repeatedly. When this happens, the adapter component must be restarted.

Perform the following steps to perform a component restart:

1. Open a terminal

2. Use the following edgecmd command: `edgecmd -cid <ComponentID> stop`

3. Use the following edgecmd command: `edgecmd -cid <ComponentID> start`