Signal Ground Strap; Sct Normal / Invert Jumper - Canoga Perkins 2240 User Manual

Canoga Perkins

2.2.3 Signal Ground Strap

The jumper selects whether chassis ground is connected directly to signal ground
(CHASSIS position) or signal ground is separated from chassis ground (FLOAT
position).
NOTE: Float can be overridden by chassis ground jumpers on
interface cards or by a jumper in the 2201 Rack Chassis.
When installed in the 2201 Rack Chassis, any modem main board,
interface, or rack chassis jumper being set to SHORT will override
the FLOAT and 100_OHM positions on all of the other modems.
CONSIDER THIS JUMPER CAREFULLY.
Factory Setting = FLOAT

2.2.4 SCT Normal / Invert Jumper

This jumper allows the SCT output from the 2240 to be normal phase or inverted
phase. The purpose of this jumper is to allow compensation for round trip transmit
clock / transmit data phase delays in situations where the customer equipment can not
return SCT as SCTE (refer to Sections 3.6 and 3.7 for discussions of transmit clock /
data phasing and SCTE use).
In the NORM position the 2240 samples TXD at the clock edge corresponding to the
appropriate standards, i.e., the 2240 samples TXD at the SCT A lead FALLING
edge.
In the INV (invert) position the 2240 samples TXD at the clock edge opposite of the
appropriate standards, i.e., the 2240 samples TXD at the SCT A lead RISING edge.
Factory Setting = NORM
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