Black Box ACS235A - Manual (Page 73)

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SERVSWITCH™ BRAND FIBER KVM EXTENDERS
3.3.3 VSYNC E
NABLE
/D
ISABLE
J
UMPER
JP9
It is possible to use the Extender to connect a VGA monitor to a computer that
outputs RGB video that superimposes CSYNC on the green signal. In this situation,
depending on the computer, the Remote Module might express only CSYNC
(composite sync) on the HSYNC lead of its VGA connector, or it might express
both CSYNC on HSYNC and VSYNC (vertical sync) on the VSYNC lead. If your
VGA monitor works fine even with both signals coming through, leave jumper JP9
installed (the factory-default setting). But if your VGA monitor’s picture becomes
distorted if the monitor receives both CSYNC on HSYNC and VSYNC on VSYNC,
remove jumper JP9 as shown in Figure 3-9; this causes the Remote Module to
suppress the VSYNC signal so that only CSYNC is expressed. Most VGA monitors,
including most of those that have problems when they receive both signals, work
well using the CSYNC signal alone.
Figure 3-9. Setting VSYNC jumper JP9.
3.3.4 SYNC-P
OLARITY
J
UMPER
JP12
With jumper JP12 installed (the factory-default setting), the Remote Module
restores the video SYNC signals to their original polarity as the Local Module
received them. Sometimes, however, you might want the Remote Module to force
both HSYNC and VSYNC to negative polarity, so that the clock is measured on the
falling edges of the signals. If you do, remove jumper JP12, as shown in Figure 3-10.
(Be careful—this jumper is right next to the reserved jumper labeled JP11; do not
change the setting of JP11.)
Figure 3-10. Setting SYNC-polarity jumper JP12.
CSYNC and VSYNC
(factory default)
CSYNC only,
VSYNC disabled
Removed Installed
Use existing polarity
(factory default)
Force negative
sync polarity
Removed Installed
JP9
JP12