Linkway S2 modem
C-32
Appendix C: VMU settings
98-150471-A02
C.9
Linkway S2 modem
C.9.1
Protocols and interfaces
The following sections describe the protocol and interface between the ACU and a LinkWay
S2 modem.
Connections
Connect the ACU and Linkway S2 modem with the following cables:
• RS-232 console cable for control communication
• 75 Ohm RF cables F-F connectors for rx and tx frequencies.
Modem signal
The $TTD command is sent by the modem to the ACU every second. The format is as
follows:
$TTD, Eb/No, RB_Detected, RB_Detected_With_No_CRC,
Rx_Synced, Tx_Synced, RB_Power,0*
Figure C-26: Connecting LinkWay S2 modem to the ACU
Figure C-27: Serial cable between the modem and the ACU
Command items
Description
$TTD
Literal string that prefixes the message
Eb/No
Eb/No measured since the last message transmission
Table C-13: Linkway S2 modem command $TTD
SAILOR900HP.book Page 32 Monday, July 18, 2016 12:44 PM
