1 jumper strap settings – CANOGA PERKINS 2270 Fiber Optic Modem User Manual
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Canoga Perkins
RS-232C
RS-423/CCITT
pin
mnem
signal name
mnem
signal direction
1
FG
Frame Ground
FG
101
n.a.
2
TXD
Transmit Data
SD
103
to modem
3
RXD
Receive Data
RD
104
from modem
4
RTS
1
Request To Send
RS
105
to modem
5
CTS
1
Clear To Send
CS
106
from modem
6
DSR
Data Set Ready
DM
107
from modem
7
SG
Signal Ground
SG
102
signal ground
8
DCD
1
Data Carrier Detect
RR
109
from modem
11
2
LT
Local Loopback Test
to modem
15
SCT
Serial Clock Transmit
ST
114
from modem
17
SCR
Serial Clock Receive
RT
115
from modem
18
2
RT
Remote System Test
to modem
24
SCTE
Tx External Clock
TT
113
to modem
1 - Only Local Handshake is supported
2 - The 2270 & 2290 Modems include a built-in Loopback Test feature. Two normally undefined lines (RS-232C pins 11 and 18)
are used for interface control of these system test functions. Refer to Chapter 5, "Troubleshooting," for a more thorough
description of this feature.
Table 3-B. RS-232C/423 Signals and Pin Assignments
Table 3-C. Available Models of RS-449/422 Interfaces
Model
Description
-22
RS-449/422 (RS low)
-H22
RS-449/422 (RS high)
-R2R
RS-449/422 (balanced CTS, RS
low)
3.3.1 Jumper Strap Settings
Jumper Strap Position
Function
W1/W2
W1
Chassis GND tied to Sig GND through 100 ohms
W2
W2Chassis GND tied directly to SIG GND
W3/W4
W3
RTS biased to "ON"
W4
RTS biased to "OFF"
Table 3-A. Jumper Strap Settings