Electrical Interfaces
DMD2401 LB/ST L-Band Satellite Modem and ODU Driver
5-18
TM075 – Rev. 1.3
Table 5-15. Asynchronous Interface - 9-Pin Female “D” Connector (J18)
Pin Number
Signal
Description
Direction
1
TX-485-B
Transmit Data RS485 (+)
Input
2
TXD-232
Transmit Data RS232
Input
3
RXD-232
Receive Data RS232
Output
5
GND
Ground
–
4
NC
Not Connected
–
9
RX-485-A
Receive Data 485 (-)
Output
8
RX-485-B/CTS
Receive Data 485 (+)
Output
6
TX-485-A
Transmit Data 485 (-)
Input
7
RTS
Request to Send
Input
5.4.17 TX DC VOLTAGE INDICATOR
The Transmit DC Voltage Indicator shows if there is DC Voltage present at J2.
5.4.18 RX DC VOLTAGE INDICATOR
The Receive DC Voltage Indicator shows if there is DC Voltage present at J1.
5.5 Async Port Configuration Switches
The switch settings listed below in Tables 5-16 through 5-19 are used to configure the Async Port
for the following applications. The DIP Switches are located on the inside of the unit on the
Async Card with the exception of the AS/3771 Daughter Card (discussed below). The user must
remove the top cover of the unit to access these switches.
