Specifications

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