# 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**:

1. **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
2. **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
3. **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**:

1. **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
```
2. **Use Configuration API**
  * If charger supports remote configuration
  * Send configuration via charger manufacturer's API
  * Verify credentials are stored after configuration
3. **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**:

1. **Verify Credentials in CPMS**
2. **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
3. **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**:

1. **Register Charger in CPMS**
2. **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**:

1. **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
```
2. **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
3. **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**:

1. Ensure root CA certificate is properly installed on the charger.
2. Ensure charger has access to Exolink.


# ✉️ – Support

If issues persist after following these troubleshooting steps:

1. 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
2. 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](mailto:support@exolink.com)