
2240 Fiber Optic Modem
59
4.5.4 DSR Jumper
The DSR jumper controls the behavior of the DSR signal. The CCITT turns DSR
OFF when the far-end 2240 modem has a local loopback active. The TEST
position causes DSR to turn OFF (negate) whenever any loopback is active at one
or both modems.
Factory Setting = CCITT
4.5.5 CH_GND Jumper
The jumper selects whether chassis ground is connected directly to signal ground
(SHORT position) or through a 100 Ohm resistor (100_OHM position).
NOTE: In the standalone model, the 100_OHM position will only
put a 100 Ohm resistor between the two grounds if the 2240's main
board SIGNAL GND jumper is set to the FLOAT position.
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 = 100_OHM
Summary of Contents for 2240
Page 1: ...Modems Model 2240 Fiber Optic Modem Users Manual...
Page 4: ...4 Canoga Perkins Model 2240 Fiber Optic Modem...
Page 15: ...2240 Fiber Optic Modem 15 Figure 1 4 2240 Functional Block Diagram...
Page 34: ...34 Canoga Perkins Table 3 E Standard Oscillator and Divide Factors...
Page 40: ...40 Canoga Perkins This page is intentionally left blank...
Page 92: ...92 Canoga Perkins Table 4 V Models D22 and D88 Connector Pin Assignments...