Datum Systems M7 Series - Table 2-15 - Overhead Interface - RS-232 (J20); Table 2-16 - Overhead Interface - RS-485 (J20)

Maintenance M7/M7L/M7LT Modular Satellite Modem
2-16 M7/M7L/M7LT - Rev. 0.05
2.3.8.4.3. Dual G.703/E1 Overhead Channel Connection (J20)
The G7 interface offers access to the ESC overhead data is on an auxiliary connector located on the
rear panel, a 9-pin female “D” sub connector J20. The pin-out of this connector is determined by the
selected multiplexer mode. The pinout for the overhead connector when configured for RS-232 is
shown in Table 2-15 and when configured for RS-485 is shown in Table 2-16.
Table 2-15 - Overhead Interface - RS-232 (J20)
J20
Pin #
Signal Name
Use
Direction
1
ESC DCD
RS-232 Advanced/Custom
Mode Connection (sync)
Output
2
ESC Rcv Data
RS-232 Advanced/Custom
Mode Connection (sync)
Output
3
ESC Send Data
RS-232 Advanced/Custom
Mode Connection (sync)
Input
4
ESC DTR
RS-232 Advanced/Custom
Mode Connection (sync)
Input
5
Ground
Ground
Ground
6
ESC DSR
RS-232 Advanced/Custom
Mode Connection (sync)
Output
7
ESC RTS
RS-232 Advanced/Custom
Mode Connection (sync)
Input
8
ESC CTS
RS-232 Advanced/Custom
Mode Connection (sync)
Output
9
RS-232 Input
Not Currently Used
Input
Table 2-16 - Overhead Interface - RS-485 (J20)
J20
Pin #
Signal Name
Use
Direction
1
ESC DCD+ (B)
RS-485 Advanced/Custom
Mode Connection (sync)
Output
2
ESC Rcv Data+ (B)
RS-485 Advanced/Custom
Mode Connection (sync)
Output
3
ESC Send Data+ (B)
RS-485 Advanced/Custom
Mode Connection (sync)
Input
4
RS-485 Input- (A)
Not Currently Used
Input
5
Ground
Ground
Ground
6
ESC DCD- (A)
RS-485 Advanced/Custom
Mode Connection (sync)
Output
7
ESC Send Data- (A)
RS-485 Advanced/Custom
Mode Connection (sync)
Input
8
ESC Rcv Data- (A)
RS-485 Advanced/Custom
Mode Connection (sync)
Output
9
RS-485 Input+ (B)
Not Currently Used
Input