Maintenance M7/M7L/M7LT Modular Satellite Modem2-16 M7/M7L/M7LT - Rev. 0.052.3.8.4.3. 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 therear panel, a 9-pin female “D” sub connector J20. The pin-out of this connector is determined by theselected multiplexer mode. The pinout for the overhead connector when configured for RS-232 isshown in Table 2-15 and when configured for RS-485 is shown in Table 2-16.Table 2-15 - Overhead Interface - RS-232 (J20)J20Pin # Signal Name Use Direction1 ESC DCD RS-232 Advanced/CustomMode Connection (sync)Output2 ESC Rcv Data RS-232 Advanced/CustomMode Connection (sync)Output3 ESC Send Data RS-232 Advanced/CustomMode Connection (sync)Input4 ESC DTR RS-232 Advanced/CustomMode Connection (sync)Input5 Ground Ground Ground6 ESC DSR RS-232 Advanced/CustomMode Connection (sync)Output7 ESC RTS RS-232 Advanced/CustomMode Connection (sync)Input8 ESC CTS RS-232 Advanced/CustomMode Connection (sync)Output9 RS-232 Input Not Currently Used InputTable 2-16 - Overhead Interface - RS-485 (J20)J20Pin # Signal Name Use Direction1 ESC DCD+ (B) RS-485 Advanced/CustomMode Connection (sync)Output2 ESC Rcv Data+ (B) RS-485 Advanced/CustomMode Connection (sync)Output3 ESC Send Data+ (B) RS-485 Advanced/CustomMode Connection (sync)Input4 RS-485 Input- (A) Not Currently Used Input5 Ground Ground Ground6 ESC DCD- (A) RS-485 Advanced/CustomMode Connection (sync)Output7 ESC Send Data- (A) RS-485 Advanced/CustomMode Connection (sync)Input8 ESC Rcv Data- (A) RS-485 Advanced/CustomMode Connection (sync)Output9 RS-485 Input+ (B) Not Currently Used Input
