Table 1, Manual overrides, Ntsc / pal operation – Adtec digital AVS2 User Manual
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The AVS2 has a user defined "TIME TO BACKUP" period, which is defined as the amount of time from the loss of valid
video (either mode1 or mode 2) to the switch to the backup source.
This is configurable with jumpers
J1 through J3, see
Table 1.
TABLE 1:
Manual Overrides
The AVS2 also allows manual override of the primary source with jumpers J6 and J7 and pins 6, 8 and 9 of the DB 9
connectors.
J6 (IN):
A contact closure from pins 9 to 8 will cause an immediate switch to the backup source, regardless of the status of the
primary video source.
J7 (IN)
A contact closure from pins 6 to 8 will cause an immediate switch to the backup source, regardless of the status of the
primary video source.
NTSC / PAL OPERATION
J10 (IN) enables detection of PAL video. Since some other minor modifications of the unit are necessary for PAL
operation, changing this jumper should only be done at the factory.
J3
J2
J1
TIME TO
BACKUP
OUT
OUT
OUT
50 mSEC
OUT
OUT
IN
225 mSEC
OUT
IN
OUT
420 mSEC
OUT
IN
IN
600 mSEC
IN
OUT
OUT
1.2 SEC
IN
OUT
IN
6 SEC
IN
IN
OUT
12 SEC
IN
IN
IN
35 SEC