What is the lock switch? How is it different between the EDR3 and EDR3C?
The Lock switch serves several roles in the recorder: The first application was to “lock” the recorder into the current operating mode. This mode was useful to help reduce aborted tests due to unintentional tampering by curious personnel. The second role is that of entering manual commands in the field. You can use the lock switch in conjunction with the select button to enter simple commands. The difference between the EDR3 and EDR3C are two-fold: The sequence of commands, and the behavior of the system when in the “active-standby” mode.
