If no manual reset key is specified in the notes of the IS description, the interlock shall auto-reset as soon as all the causes of activation return to "normal" (non-trip) values. The final elements shall act as follows:a) all control valves shall reset to manual mode and will automatically assume the safe position. The operator shall manually put the valve back in AUTO mode according to the operating requirements. b) all machines (pumps, compressors &c.) shall be restarted manually by the operators (exceptions are the auto-restart interlocks).c) the on-off valves that do not have an OPEN-CLOSE HS shall reset to the "normal"(i.e., operating) position. d) the on-off valves that have an OPEN-CLOSE HS shall be kept in the position they have when the interlock is active (typically the safe position). The board operator shall then operate the valves to open/close them. All exceptions to the above shall be clearly indicated in the relevant interlock description.