CANOGA PERKINS 2270 Fiber Optic Modem - Manual (Page 15)

15
2270 Fiber Optic Modem
Table 1-D. 2270 Jumper Functions
SIGNAL GROUND controls connecting circuit ground to the chassis.
CHASSIS connects them together.
FLOAT isolates the two grounds.
Factory Setting = FLOAT
SCT POLARITY controls the transmit clock output.
NORM is always used for low data rates for proper clock phasing.
INV may be needed for internal clock or slave clock modes operating high data rates
if the DTE loop has long delays.
Factory Setting = NORM
TEST controls the built-in test pattern checker.
ON allows System Test loopback to be activated and Remote Loopback control.
OFF defeats pattern loopback for System Test and disables any Remote Loopbacks.
Factory Setting = ON
ALT A and ALT B allow alternate loopback methods to be selected. If the front panel alternate
loopback switch is also considered, there are eight possible loopback responses for
each end of the link.
ALT A affects Local Loopback, depending on the ALT loopback switch.
Factory Setting = OFF
ALT B affects Remote Loopback, depending on the ALT loopback switch.
Factory Setting = OFF
EIADSR allows a proper DSR signal to connect to the interface.
ON connects the signal through interface.
OFF disconnects the signal from the interface. Only the DS1/T1 interface requires
this selection.
Factory Setting = ON