A door interlock coordinates normal passage through related doors. It uses a defined sequence and feedback from the openings; it does not itself create room pressure, verify particle cleanliness or prove that an airlock has recovered after a transfer.
Describe the permitted movement
Mark the doors that belong to each group and the routes people or materials must follow. State which door may be released under each normal condition. Avoid making unrelated openings inhibit one another merely because they share a controller.
SDC's door-controller instructions distinguish normally locked and normally unlocked interlocking modes. These arrangements respond differently to an opening or access request. Select the sequence for the application, then check that the controller, locks and feedback devices support it.
Keep commands and actual states separate
| Information | What it establishes |
|---|---|
| Release command | The controller has requested a lock action. |
| Door-position contact | The sensor reports the leaf's position. |
| Lock-status feedback | A compatible device reports a separate locking condition. |
These signals should not silently substitute for one another. A misaligned leaf, faulty closer or obstructed threshold is a mechanical problem that the controller cannot solve. Plan contact adjustment and service access with the door hardware.
Preserve the required escape function
Normal sequencing must be coordinated with the approved escape and fire strategy. Agree the response to emergency release, loss of power and equipment faults before ordering the locking package. A generic interlock board is not an approval for a complete exit arrangement.
For US workplaces, OSHA's exit-route requirements address the ability to leave and failures that could restrict emergency use. The applicable local requirements and the particular installation still need to be resolved by the responsible project specialists.
Acceptance should cover simultaneous requests, a held-open door, inconsistent feedback and restoration after interruption, as well as the normal route. Retain the agreed sequence and device schedule so a later component replacement does not alter the intended behaviour.
For door interlock systems, send shengtongjh the door-group plan and approved control requirements to coordinate the controller, indication and hardware interfaces.