Occupancy Sensor False Negative Diagnostic - Solar Faults | terminalfaults.org

Technical Background:

Occupancy sensors typically transmit data via a TLS/SSL encrypted API endpoint. Malformed JSON payloads, API 500-series errors (server-side), or incorrect token validation may cause the 'Parking Space Unavailable' message. Data serialization/deserialization errors at the API level may also contribute.

Symptoms:

The system reports 'Parking Space Unavailable' despite the space potentially being vacant. The occupancy sensor is incorrectly signaling a negative state, causing an application-level error.

Possible Causes:

API endpoint is experiencing intermittent errors (500, 502, 504).
Invalid or expired authentication token preventing data transmission.
Cache invalidation issues causing stale data to be displayed.
DNS resolution failure preventing the sensor from reaching the API endpoint.
TLS/SSL certificate expiry or misconfiguration causing connection refusal.
Data parity errors between the sensor and the cloud application. Verify JSON payload structure.

Solution:

1

Verify the API endpoint status using a monitoring tool or by querying the endpoint directly. Check for 5xx errors.
2

Clear the application cache on the kiosk terminal and restart the application.
3

Check the system's DNS settings to ensure they are correctly configured and can resolve the API endpoint's domain name.
4

Verify that the TLS/SSL certificate for the API endpoint is valid and properly configured.
5

If using tokens for authentication, check for token expiry or invalid token formats. Attempt to refresh the token.
6

Review the API request and response payloads for JSON parity and proper data formatting. Validate JSON schemas.
7

Trigger a software reset of the occupancy sensor through the kiosk management software (if available).

Safety Warning:

Exercise caution in public areas. Do not tamper with the kiosk hardware. Report any persistent issues to the appropriate IT support personnel. External temperatures can impact electronics; maintain a functional HVAC system.

Prevention:

Implement regular API monitoring to detect and address endpoint issues promptly. Establish a robust token management system with automated renewal. Enforce regular cache clearing procedures. Implement robust error handling within the kiosk application to gracefully handle API errors.

Expert Tip:

Try clearing the DNS cache on the kiosk terminal. Corrupted DNS entries can lead to intermittent connectivity issues. The command depends on the OS, but often involves flushing the DNS resolver cache (e.g., `ipconfig /flushdns` on Windows via remote session).

Frequently Asked Questions

•What is the IP address and FQDN of the sensor API?

Obtain from network documentation.

•What is the current SSL certificate expiration date?

Check using openssl or web browser.

•What is the typical JSON payload size sent from the sensor?

Capture sample payloads via packet sniffing and analyse the sizes.

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•What is the IP address and FQDN of the sensor API?

•What is the current SSL certificate expiration date?

•What is the typical JSON payload size sent from the sensor?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: