Lathem AirTime AT-MSX - Manual (Page 3)

Installation & User’s Guide
Page 1
Operation
When connected to AC power, the AT-MSX automatically
powers up and an LED on the case bottom flashes 3 times then
begins flashing every 2 seconds indicating that the AT-MSX is
waiting to receive an AirTime radio signal. The LED will flash
brighter upon receipt of an AirTime signal. The AT-MSX will set
its internal clock to the exact time and the LED will flash every
second to indicate normal operation. The unit will transmit
the Lathem RS485 digital signal once per minute, to provide
time synchronization to other Lathem devices. It also closes
the dry relay contact for two (2) seconds once per day at 23
hours 59 minutes and 58 seconds to provide a synchronization
time reference signal to external third party devices such as an
intercom system.
Physical
The AT-MSX contains a microprocessor and UHF radio receiver
housed inside an impact resistant keyhole wall mount plastic
enclosure. The bottom of the enclosure features a five (5)
place removable terminal block connector for wiring to
external devices, a red LED signal reception indicator, four (4)
position program jumpers, and power port for an external AC
power adaptor.