Start with the operating requirement
Loss-of-link behavior must be agreed and tested for the complete system and operating mode. Begin with the site, intended operation and authority requirements. Record assumptions beside the requested configuration so the supplier, integrator and installer are reviewing the same system. The article is a buyer's planning resource; final design, compliance and operating decisions remain project specific.
Information to define before quotation
| Field | What to record | Why it matters |
|---|---|---|
| Loss detection | Heartbeat, timeout and supervision interval | Defines when a fault is declared |
| Local response | Indication state, sequence and operator alert | Makes the behavior observable |
| Peer behavior | How other signal units respond | Checks coordinated system behavior |
| Recovery | Automatic or authorized restart and state reconciliation | Prevents conflicting assumptions |
| Record | Time, unit, cause, state and restoration | Supports maintenance and acceptance |
Use a controlled review sequence
- Loss detection: Heartbeat, timeout and supervision interval Defines when a fault is declared
- Local response: Indication state, sequence and operator alert Makes the behavior observable
- Peer behavior: How other signal units respond Checks coordinated system behavior
- Recovery: Automatic or authorized restart and state reconciliation Prevents conflicting assumptions
- Record: Time, unit, cause, state and restoration Supports maintenance and acceptance
Give every important item an owner and a document reference. Where a value comes from a drawing, tender, authority instruction or product datasheet, identify that source and revision. Mark unresolved items rather than filling gaps with a catalogue assumption.
Build acceptance around observable evidence
Translate the approved requirements into checks that an independent witness can repeat. State the test setup, equipment identity, initial condition, expected result, measured or observed result and any deviation. Keep photographs, data exports and signed records with the relevant model, firmware or drawing revision.
A passing result for one configuration does not automatically cover a different voltage, optical assembly, interface, battery, mounting arrangement or software release. Define which differences require a document review, sample approval or repeated test.
Common specification mistakes
- Describing the system only during normal connection
- Testing one head without observing the other units
- Allowing reconnection to clear evidence needed for diagnosis
These errors usually appear when a quotation is based on a short product name instead of a system description. A clear schedule and acceptance record reduce rework during sample approval, production and commissioning.
Prepare the supplier enquiry
Send the project location, intended use, quantity, destination, applicable tender or standard, required interfaces, operating conditions and requested documents. Ask the supplier to identify confirmed items, options and exceptions in writing. For GAOQIAO catalogue options, start from the relevant product category and request the current drawing and data for the exact offered model.
Frequently asked questions
What is the correct signal state after link loss?
That is project and product specific. It must be defined by the responsible traffic authority and verified against the approved system behavior.
Should recovery be automatic?
Only when the approved design defines prerequisites and a safe reconciliation sequence. Record the actual product behavior.
Can this test be performed on an open road?
Testing must follow the authority-approved traffic management and safety procedure; use a controlled environment where required.