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Can't Connect

Connection or authentication issues are preventing access. Here's how to diagnose and fix them.

Quick Diagnosis

Check these first:

  1. Is the data source reachable? Verify network connectivity
  2. Are credentials correct? Check connection string, keys, tokens
  3. Has anything changed? Keys rotated, firewall rules, network changes

Step-by-Step Diagnosis

1. Check Connection Status

In your workspace, check the connection status indicator:

StatusMeaningAction
ConnectedWorking normallyIssue is elsewhere
ConnectingAttempting connectionWait, then retry
ErrorConnection failedCheck details below
DisconnectedNot attemptingCheck configuration

2. Verify Credentials

The most common cause is credential issues:

For IoT Hub connections:

  • Check the connection string is complete
  • Verify the shared access policy has correct permissions
  • Ensure the key hasn't been rotated

For Event Hub connections:

  • Check namespace and event hub names
  • Verify connection string includes EntityPath
  • Check SAS token hasn't expired
Thinking Tip:

If credentials recently changed in Azure, you'll need to update them in OpenIndustrial. Changes don't sync automatically.

3. Check Network Access

Firewall and network issues:

SymptomLikely CauseSolution
Timeout errorsFirewall blockingAdd OI IPs to allowlist
Connection refusedPort blockedCheck port 443/5671 open
SSL errorsCertificate issueVerify SSL/TLS settings

4. Test the Source Directly

Before troubleshooting further, verify your data source works:

For IoT Hub:

  1. Can you see device telemetry in Azure Portal?
  2. Is the device registered and sending data?
  3. Does the device show "Connected" in Azure?

For Event Hub:

  1. Can you see messages in Azure Portal?
  2. Is the producer sending events?
  3. Are consumer groups available?

Common Error Messages

"Connection string is invalid"

Cause: Malformed or incomplete connection string

Solution:

  1. Copy the full connection string from Azure Portal
  2. Ensure no characters are truncated
  3. Check for extra spaces or line breaks

"Authentication failed"

Cause: Invalid credentials or expired token

Solution:

  1. Regenerate keys in Azure Portal
  2. Update connection in OpenIndustrial
  3. Verify policy permissions

"Resource not found"

Cause: Incorrect resource name or deleted resource

Solution:

  1. Verify the resource exists in Azure
  2. Check spelling of namespace/hub name
  3. Ensure you're in the correct Azure subscription

"Connection timeout"

Cause: Network issue or firewall blocking

Solution:

  1. Check firewall allows outbound HTTPS
  2. Verify network connectivity
  3. Check for proxy configuration needs

Azure-Specific Issues

IoT Hub

Common issues:

  • Using device connection string instead of IoT Hub connection string
  • Missing ServiceConnect permission on policy
  • Consumer group already in use

Event Hub

Common issues:

  • Missing EntityPath in connection string
  • Consumer group doesn't exist
  • Partition count changed

Still Can't Connect?

Gather this information:

  1. Exact error message
  2. Connection type (IoT Hub, Event Hub, etc.)
  3. When it last worked (if ever)
  4. Any recent changes
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