Comtech EF Data SDM-309B - Manual (Page 92)

SDM-309B Satellite Modem M&C and Interfaces
MN/U-SDM309B Rev. # 4-4–15
TERRESTRIAL TX DATA TERESTXDAT 5
ENGINEERING SERVICE CHANNEL RXESCDAT 7
RS-422/V.35 RECEIVE TIMING SCR/RTA
SCR/RTB 23
24
RS-422/V.35 TRANSMIT TIMING SCT/STA
SCT/STB 21
22
RS422/V.35 TERMINAL TIMING SCTE/TTA
SCTE/TTB 12
13
RS422 TRANSMIT OCTET R422TXOA
R422TXOA 14
15
RS422 RECEIVE OCTET R422RXOA
R422RXOB 8
9
RS422/V.35 REQUEST TO SEND RTSA
RTSB 45
29
V.35 DATA SET READY V.35_DSR 41
RS422/V.35 CLEAR TO SEND CTSA
CTSB 47
31
RS422/V.35 DATA SET READY DSR/DMA
DSR/DMB 48
32
RS422/V.35 RECEIVER READY RRA/RLSD
RRB/RLSD 46
30
PRIMARY ALARM OUT PRI_COM
PRI_NO
PRI_NC 10
43
27
SECONDARY ALARM OUT SEC_COM
SEC_NO
SEC_NC 11
44
28
MODULATOR FAULT MOD_FLT 49
DEMODULATOR FAULT DEM_FLT 33
4.2.1.8 IBS Interface Specification
Common Interface Specifications
Transmit Clock Reference TX_Terrestrial (derived from TT, SCTE, or SD)
Internal (10
-5 accuracy) External Reference
(differential receiver)
Buffer Clock Reference TX_Terrestrial (derived from TT, SCTE, or SD)
Satellite (bypass) External Reference (differential
receiver) Internal (10
-5 accuracy)
Modulator Fault Open collector output
15 V max
20 mA max current sink
Fault is open circuit
Demodulator Fault Open collector output
15 V max
20 mA max current sink
Fault is open circuit
External Clock Characteristics Amplitude: Differential .5 - 5 V p-p
Common Mode 0 - 2.5 VDC
Frequency: 8 KHz to 10 MHz, in 8 KHz Steps
Impedance: 100
!
Waveshape: Sine or Square
Duty Cycle: 50 ± 10%
Earth Station to Earth Station Channel RS-232 TD, RD, DSR, RTS, CTS
Asynchronously sampled at 1/512 of the primary
channel data rate for a usable data rate equal to
1/2000 of the primary channel data rate.