MODEL 2099-42 CLOCK GENERATOR
SECTION 1 GENERAL
1.1 Equipment Description- The Model 2099-42 Clock Generator provides two RS422 clock signals
selectable from 256, 192, 128, 96 or 64 kHz locked to an external 10 MHz reference and generated from a
12.288 MHz VCXO. Level detection circuitry provides an alarm signal if the external 10 MHz signal is
removed and automatic switching tunes the VCXO in the PLL to 12.28800 MHz until the 10 MHz clock is
restored. LEDs indicate PLL and Level alarms, Manual operation, and selection of internal or external (lock to
10 MHz) control of the VCXO. A front panel switch manually selects internal or external (lock to 10 MHz)
control of the VCXO. Diodes on the DC inputs allow operation from redundant power supplies. An open
collector indicates Manual operation and relay contacts indicate a major alarm due to loss of PLL lock or 10
MHz reference. The unit is housed in an aluminum extrusion chassis and can be mounted on an 1 3/4”, rack
panel (Option -R). A 115 VAC wall power supply provides DC power to the 2099-42.
20 99-42 CLOCK GENERATOR
C
ROSS
T
ECHNOLOGIES, INC.
EXT. AUTO INT.
INT FREQ.
INT/
EXT
MAN
PLL
ALM
REF
ALM
MODE
MONITOR
RS422
CLOCK
OUT
10
MHZ IN
DIVI-
DER
PLL
LEVEL
DET..
AUTO
EXT
INT
INT / EXT
SELECT
VCXO INT.
FREQ.
12.288
MHZ VCXO
A
2099-42 BLOCK DIAGRAM
B
DIVI-
DER
FIGURE 1.1 2099-42 Clock Generator Block Diagram and Front Panel
2099-42 manual Rev. A
Page 3
10/27/2005
