Lathem DWA-S Sonachron Signal Control The Sonachron Program Timer from Lathem is ideal for schools and industry. The Sonachron is user-friendly, with a front-mounted keypad that lets you program the exact minute and weekday(s) of each event. Sonachron Features An optional dip switch can be set for operating the unit as a control device. As a control device, the relay latches On or Off according to your schedule. A keypad allows easy programming and changes to schedule for operating the internal 10-amp dry contact relay. The weekly schedule can have up to 1,440 events. Each event includes the day(s) of the week and the time. Signal duration can be set from 1 to 99 seconds. If desired, a 4-digit security code entry can be required by keypad for preventing unauthorized tampering. An internal battery retains memory and timekeeping during power failures lasting up to 7 days.