LTRx-512 User’s Guide

Welcome

Thank you for purchasing your new MASTER CLOCK. You can use your new Master to

ring bells or turn on circuits for up to 99 seconds, as well as to synchronize the time on

secondary wall clocks or devices. This manual covers 3 models of MASTER clocks: the

LTR4-512, the LTR8-512 and the LTR8-512M

LTR4-512 LTR8-512 LTR8-512M

System Clock
Correction
1 correction type running,
plus RS485 correction
Up to 2 like or dissimilar
correction types running
simultaneously, plus RS485
correction
Up to 2 like or dissimilar
correction types running
simultaneously, plus RS485
correction
Bell Circuits 4 with no clock correction
2 with 1 clock correction
8 with no clock correction
6 with 1 clock correction
4 with 2 clock correction
8 with no clock correction
6 with 1 clock correction
4 with 2 clock correction
Certifications UL, cUL,
UL, cUL,
FCC, DOC (internal modem)
UL, cUL,
FCC, DOC (internal modem)
PC Interface Software None RS-232, RS-485
RS-232, RS-485,
Modem
Atomic clock
synchronization
No No Yes. Requires the
MasterLink software
Remote Schedule
selector switch
(optional)
No Yes Yes

If your Master has 4 lights on the front panel, then you have the model LTR4-512

CLK 1
1 2 3 4
cancel enter
123
456
78
9
0
*
#

If your Master has 8 lights at the left of the front panel, then you have the model LTR8-512. If

the TR light at the keypad is lit, then you have the model LTR8-512M

SD
TR
RD
CD
CLK 2 CLK 1
1234
5 6 7 8
cancel enter
123
456
78
9
0

*

#

4