User Manual Part 2

IS-900 User Guide Page 141 of 159
15.2. Configuring the IS-900 for GENLOCK
The default operation of the tracker is free run. That is, the tracker performs updates
and, in continuous mode, outputs data records as rapidly as it can. GENLOCK
operation causes the tracker to synchronize updates and data record output to an
external sync signal or to an internal clock. When external GENLOCK is enabled and a
valid sync signal is provided, it may take several seconds to stabilize tracking. If a valid
signal not present, the tracker will wait an extra period for the signal, dropping the
update rate to half the sync rate. Details are discussed below.
Connecting Sync Signal
The external sync signal for GENLOCK on an IS-900 is on the back panel of the
processor shown in Figure 44.
Figure 44 - Back Panel of IS-900, SYNC IN is External GENLOCK Input
Connect the sync signal to the BNC connector labeled SYNC IN on the back of the IS-
900 Processor. The input interface setting for SYNC IN is controlled by software and
access is provided via command or the LCD menu. This setting is saved with the rest of
the user settings.
Command: MGS[source]<>
source 1 TTL
2 NTSC
Default is TTL. If source is omitted, the current setting is returned (31GS{source}<>).
From the LCD menu, GENLOCK source is selected by choosing: System config →
GENLOCK → Source (TTL and NTSC options only).