Charger Connection Troubleshooting Guide

This page provides troubleshooting steps for common charger connection errors encountered when charge points attempt to connect to Exolink.

🔧 – Error Types and Solutions

401 Unauthorized - No Credentials Sent

Description: The charger is attempting to connect without providing any authentication credentials.

Possible Causes:

Charger firmware configuration missing
Network proxy stripping authorization headers
Incorrect WebSocket/HTTP client implementation

Solutions:

Verify Charger Configuration
- Access charger’s local configuration interface
- Ensure Basic Authentication or certificate-based authentication is enabled
- Confirm credentials are saved in charger’s persistent storage
Check Network Path
- Test direct connection bypassing proxies/firewalls
- Verify authorization headers are not being stripped by intermediate network devices
- Use network packet capture to confirm headers are being sent
Firmware Update
- Update charger firmware to latest stable version
- Some older firmware versions have known authentication bugs

401 Unauthorized - Credentials Not Set

Description: The charger has empty or null credential fields in its configuration.

Possible Causes:

Initial provisioning incomplete
Factory reset without reconfiguration
Configuration corruption

Solutions:

Re-configure Charger

Steps:
1. Access charger admin panel (usually via local IP)
2. Navigate to OCPP Configuration
3. Set Authentication Method: Basic Auth
4. Enter Username: [charger_identity]
5. Enter Password: [generated_password]
6. Save and restart charger

Use Configuration API
- If charger supports remote configuration
- Send configuration via charger manufacturer’s API
- Verify credentials are stored after configuration
Manual Configuration via Serial/USB
- Connect to charger’s service port
- Use manufacturer’s configuration tool
- Set credentials directly in firmware settings

401 Unauthorized - Invalid Credentials

Description: Credentials are provided but don’t match CPMS records.

Possible Causes:

Incorrect password or username
Charger identity mismatch
Expired or rotated credentials
Case sensitivity issues

Solutions:

Verify Credentials in CPMS
Reset Charger Password
- Generate new password in CPMS admin
- Update charger configuration with new password
- Ensure password meets OCPP security requirements:
  - Minimum 8 characters
  - No special characters that might be URL-encoded incorrectly
Check Identity Format
- Ensure charger identity matches exactly (case-sensitive)
- Remove any trailing spaces or special characters

404 Not Found - Charger Not Registered in CPMS or Exolink

Description: The charger identity is not found in the CPMS or Exolink database.

Possible Causes:

Charger never registered
Wrong tenant/organization
Identity format mismatch
Charger was deleted

Solutions:

Register Charger in CPMS
Check Identity Formatting
- Compare charger’s reported identity with CPMS records
- Common issues:
  - Charger sends: VENDOR_MODEL_123
  - CPMS expects: vendor-model-123
- Update either charger config or CPMS record to match

429 Too Many Requests - CPMS Throttling

Description: The charger is exceeding rate limits set by the CPMS.

Possible Causes:

Connection retry loop
Excessive heartbeat frequency
Multiple chargers behind same IP
DDoS protection triggered

Solutions:

Adjust Charger Settings

Recommended OCPP Configuration:
- HeartbeatInterval: 300 (5 minutes minimum, check your CPMS for recommendation)
- ConnectionRetryInterval: 30-60 seconds
- MaxConnectionRetries: 3-5 attempts
- WebSocketPingInterval: 60 seconds

Check for Connection Loops
- Review charger logs for rapid connect/disconnect cycles
- Common causes:
  - Immediate reconnect on WebSocket close
  - Missing error handling causing restart loops
- Add proper error handling and delays
CPMS Rate Limit Configuration
- Possible limits per charger IP:
  - Connection attempts: 10 per minute
  - API calls: 100 per minute
  - WebSocket messages: 1000 per minute
- Contact CPMS administrator to adjust if legitimate traffic

No Error Message

Description: The charger is unable to reach Exolink.

Possible Causes:

Certificate issues
Network issues (VPN / Firewall / SIM)

Solutions:

Ensure root CA certificate is properly installed on the charger.
Ensure charger has access to Exolink.
Ensure CPMS URL is publically reachable and not private.

✉️ – Support

If issues persist after following these troubleshooting steps:

Collect diagnostic information:
- Charger identity and Exolink tenant
- Charger model and firmware version
- Exact error messages and timestamps
- Network topology diagram
- Packet capture if possible
Contact appropriate support channel:
- Charger hardware issues: Manufacturer support
- CPMS access issues: Platform administrator
- Network issues: IT/Network team

We will be happy to help you 😊

We get back to you as soon as possible.

✉️ support@exolink.com