32
LDM-MR19.2
Table 4-2. Strap Selection, Card Version
Strap Identity Function
Possible
Standard
Settings
Factory Settings
No. 1
Determines the data rate.
0 = 19.2 Kbps
DATA RATE
1 = 14.4 Kbps
(Kbps)
2 = 9.6 Kbps
2 = 9.6 Kbps
3 = 7.2 Kbps
4 = 4.8 Kbps
5 = 3.6 Kbps
6 = 2.4 Kbps
7 = 1.2 Kbps
No. 2
Determines whether the transmit-timing
INT
INT (internal clock)
XMT TIMING
signal comes from the internal clock,
EX
external clock, or receive clock, or
RCV
whether the unit operates in async.
ASY
No. 3
Determines whether the unit uses
2W
2W/4W
2 wires or 4 wires.
4W
4W (4 wires)
No. 4
Determines the RTS-to-CTS delay.
0 ms
CTS DELAY
8 ms
8 ms
64 ms
No. 5
Determines the transmit carrier mode.
ON
ON
CARRIER
ON: Transmit carrier is constantly ON.
CTRL
CTRL: Transmit carrier is ON only when
RTS is high.
CTRL should be used in multipoint
applications.
No. 6
Determines transmit-output level to the
0 dBm
0 dBm
XMT LEVEL
line.
–3 dBm
–6 dBm
–9 dBm
No. 7
Determines transmit-line impedance.
600
XMT IMPD
For multipoint applications, set the
300
master modem to LOW.
150
150 [ohms]
LOW
No. 8
Determines receive-line impedance.
150
150 [ohms]
RCV IMPD
For multipoint applications, set the
300
master modem and the last modem in
600
line to 150; set all others to HIGH.
HIGH
No. 9
Enables/disbales Analog loopback
EN
EN
PIN 18
command from the DTE on Pin 18.
DIS
No. 10
Enables/disables Remote loopback
RLB EN
RLB EN
PIN 21
command from the DTE on Pin 21.
RLB DIS
