CANOGA PERKINS 2240 Fiber Optic Modem - Manual (Page 89)

2240 Fiber Optic Modem
89
Table 4-U.
Jumper Strap
Options
JUMPER DESCRIPTION FACTORY CONFIGURATION
ID TW TW8 T22 T88 D22 D88
W3 / W4* W3 = VCO disabled W4 W4 W4 W4 W4 W4
W4 = VCO enabled
W5 / W6** W6 = Normal SCT W6 W6 W6 W6 W6 W6
W5 = Inverted SCT
W5 / W6 W7 = Shield connected to W7 W7 W7 W7 W7 W7
chassis ground
W8 = Shield connected to
signal ground
W9 / W10 W9 = Chassis ground W10 W10 W10 W10 W10 W10
connected to signal ground
W10 = Not connected
E2 TxD RCV termination N/A IN N/A IN N/A IN
resistor
E3 SCTE RCV termination N/A IN N/A IN N/A IN
resistor center tap to shield
ground
* W3 / W4 jumper option may not exist on some older versions. It is only required
when performing Local loopbacks. The W4 position corrects the duty cycle of
External Clock above 9 Mbps.
** The W5 / W6 jumper option serves the same function as the SCT Normal / Invert
Jumper on the main 2240 board. Either one may be used to invert SCT.
Refer to Section 2.2.5 for details.