User Manual Part 2

User Guide to Q4000/QPRO
Document Number 1135-4713 Rev G
THIS DOCUMENT CONTAINS CONFIDENTIAL AND PROPRIETARY INFORMATION OF QUAKE GLOBAL CORPORATION. IT MAY BE USED BY
RECIPIENT ONLY FOR THE PURPOSE FOR WHICH IT WAS TRANSMITTED AND WILL BE RETURNED UPON REQUEST OR WHEN NO LONGER NEEDED
BY RECIPIENT. DISCLOSURE TO UNAUTHORIZED THIRD PARTIES OR DUPLICATION WITHOUT THE EXPRESS WRITTEN PERMISSION OF QUAKE
GLOBAL IS PROHIBITED.
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5.1.2 Receive mode
If the modem is in Receive mode, the receiver has acquired a satellite. When in this mode, a
typical message sent to the Logger would be:
Rx[26Jun02 22:30:06|11.00] Sync(23* 285 04): Dplr -2448 Pwr -103 Ebno 15.8 0/50
where:
• Rx: Indicates a satellite signal is being received.
• 26Jun02 22:30:06: GMT according to the satellite.
• 11.00: Indicates how many seconds the modem has been receiving from the current
satellite.
• Sync: Indicates a Synchronization Segment.
• (23* 285 04): Indicates that satellite number 23 is currently being received, on downlink
channel 285. The asterisk indicates that the satellite is currently usable for
communications. The 04 is the downlink frame number.
• Dplr -2448: Estimated Doppler frequency in Hz. This is the relative position of the
satellite to the modem. A positive number means the satellite is moving towards the
modem; a negative number means the satellite is moving away from the modem.
• Pwr -103: Estimated Power level in dBm. When the satellite is in view this is the
satellite’s signal strength; when the satellite is not in view this is the amount of noise on
this frequency.
• Ebno 15.8: Estimated Signal/Noise ratio in dB. The larger this number is, the better the
connection.
• 0/50: Bad/Total Segment Count. 0/50 indicates 50 Downlink Segments were received in
the previous frame, with 0 checksum errors.
5.2 Iridium
Iridium messages are displayed like modem commands with the label “[IRI]” at the beginning. Tx
stands for Transmit; Rx stands for Receive. Below are some common Iridium messages:
5.2.1 Request signal strength
Tx[IRI]T+CSQ: Request signal strength reading (performed every 10 seconds)
Rx[IRI]+CSQ:1: A signal strength of 1 is barely readable. Maximum is 5.
Rx[IRI]OK
5.2.2 Check modem status
Tx[IRI]+SBDSX: Request modem status (performed every 20 seconds). If a message is
available for the modem, generate Ring Alert.
5.2.3 Ring Alert sequence
Received MSG_ALERT!!! The modem has received a Ring Alert from the satellite.
Tx[IRI]AT+SBDRB: Short Burst Data Read Byte is an attempt to see if the message is
already in the modem’s message queue.