Specifications

Asynchronous Overhead Channel Unit SDM-650B Satellite Modem
F–8 Rev. 5
F.2 ASYNC Interface Connector Pinouts
The ASYNC interface is provided on a 50-pin female D connector accessible from the
rear panel of the modem. Screw locks are provided for mechanical security of the mating
connector.
Signal Function Name Pin #
GROUND GND 1, 2
T1E1 SEND DATA A T1E1-SDA 34
T1E1 SEND DATA B T1E1-SDB 18
EXTERNAL CLOCK A EXCA 35
EXTERNAL CLOCK B EXCB 19
T1E1 RECEIVE DATA A T1E1-RDA 36
T1E1 RECEIVE DATA B T1E1-RDB 20
TX DATA B (ASYNC) TXD-B 4
SEND DATA A SDA 37
SCT SIGNAL A SCT/STA 21
TX DATA A (ASYNC) TXD-A 5
SEND DATA B SDB 38
SCT SIGNAL B SCT/STB 22
RX DATA B (ASYNC) RXD-B 6
RECEIVE DATA A RDA 39
RECEIVE CLOCK A SCR/RTA 23
RX DATA A (ASYNC) RXD-A 7
RECEIVE DATA B RD-B 40
RECEIVE CLOCK B SCR/RTB 24
TRANSMIT TIMING A SCTE/TTA 12
REQUEST TO SEND A RTSA 45
REQUEST TO SEND B RTSB 29
TRANSMIT TIMING B SCTE/TTB 13
RECEIVER READY A RLSD/RRA 46
RECEIVER READY B RRB 30
RS422 TX DATA A R422TXDA 14
CLEAR TO SEND B CTSB 31
DATA SET READY A DSR/DMA 48
DATA SET READY B DMB 32
CTS A CTSA 47