Fixing what you cannot touch.
WHAT MAKES IT DIFFICULT
No physical access Limited visibility Problems that occur intermittently Devices that stop reporting entirely
WHAT TO BUILD IN ADVANCE
Diagnostic reporting: resets, errors, memory, signal
Log retrieval on request The ability to increase logging temporarily A self-test the device can run
WHY TEMPORARY LOGGING MATTERS
Detailed logging cannot run continuously on constrained devices, but is needed when investigating.
WHAT TO RECORD ACROSS RESTARTS
The reason for the last restart.
WHY
It distinguishes a crash from a power loss from a commanded restart.
WHAT COMMON CAUSES ARE
Power problems Connectivity degradation Memory exhaustion over time Sensor failure Firmware defects triggered by specific conditions
WHAT MEMORY EXHAUSTION LOOKS LIKE
Devices working initially and failing after days or weeks.
WHAT TO TEST FOR IT
Long-duration running, before deployment.
WHAT TO CORRELATE
Failures against location, firmware version, hardware batch and time.
WHY
It usually identifies the cause immediately.
WHAT TO PROVIDE FIELD STAFF
A way to check a device on site without specialist equipment.
