CANOGA PERKINS 2240 Fiber Optic Modem - Manual (Page 54)

2240 Fiber Optic Modem User Manual Chapter 4 Data Interfaces
Multi-Channel Interfaces
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4.5.3 CTS_GATE Jumper
The CTS_GATE jumper controls the state of CTS when the local RTS is ON. When the jumper is
in the ON position, CTS follows RTS only. The CD position allows the 2240’s standard data
interface signal CD to gate CTS. In the CD jumper position and with local RTS ON, CTS will turn
ON either when the modem’s fiber optic receiver is in sync (main PCBA internal switch S1 CD/
DCD = OFF and CD/SYNC = ON) or the RTS signal at the far end is ON (main PCBA internal
switch S1 CD/DCD = ON and CD/SYNC = OFF). Refer to section 2.1.3.1 for more information on
the internal switch S1 CD/DCD and CD/SYNC positions.
Factory setting: ON
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
4.6 Multi-Channel Interfaces
4.6.1 RS-449/RS-423 Model MC1
This interface includes two physical connectors. The RS-449/422 uses a 37-pin, female D-Type
connector and the RS-423 uses a 25-pin, female D-Type connector.
A typical application for this interface is to transport data and dialer information from a video
location to the network equipment over fiber optic cable. The RS-449 interface can carry the
Video Codec data with the control lead used for call set up. The RS-423 interface can carry either
serial RS-232 data or parallel RS-366A data for the dialing equipment, when used with the
appropriate RS-366A adapter (2240-366-ACE or 2240-366-DTE) or equivalent cables.
Table 4-8 delineates the adapter wiring necessary to utilize the RS-423 for both the DTE (Data
Terminal Equipment) and ACE (Automatic Calling Equipment) ends.