Black Box ACS236A, ACS235A manual Setting Vsync jumper JP9

SERVSWITCH™ BRAND FIBER KVM EXTENDERS

3.3.3VSYNC ENABLE/DISABLE JUMPER 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.

CSYNC and VSYNC	CSYNC only,
(factory default)	VSYNC disabled

JP9

InstalledRemoved

Figure 3-9. Setting VSYNC jumper JP9.

3.3.4SYNC-POLARITY JUMPER 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.)

Use existing polarity	Force negative
(factory default)	sync polarity

JP12

InstalledRemoved

Figure 3-10. Setting SYNC-polarity jumper JP12.

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