SATCOM (Serial Modem)

SATCOM is an external satellite communicator used as a backup transport for reports when the primary IP/cellular path is unavailable. In Antares, SATCOM communication is handled through RS232 serial modem mode.

Overview

Operational behavior:

• SATCOM is typically used as a fallback channel when a GPRS-IP destination is unreachable.
• Reports for SATCOM destinations are configured by adding P16 in destination address configuration.
• The serial port must operate in SATCOM mode to exchange messages with the modem.
• Messages are kept in buffer until modem/server confirmation is received.
• SATCOM mode persists across resets and power cycles.

Communication notes from reference behavior:

• Serial settings: 19200 bps, 8N1.
• Event message length may reach up to 300 bytes.

Main SATCOM features:

• Global operation through Iridium satellite network.
• RS232 transparent communication.
• External high-gain Iridium antenna support.

XASM Commands

XASMM — Modem Mode

Query or configure the modem operating mode.

Query: >QXASMM<

Returns the current modem mode and buffer size.

Response: >RXASMM{mode}0{size}<

• {mode}: Modem mode (0 = disabled, 1 = enabled)
• {size}: Buffer size in bytes (4 digits, e.g., 0560)

Example:

>QXASMM<
>RXASMM100560<

Set: >SXASMM{mode}<

Enable modem mode with default buffer size.

• {mode}: 0 = disable, 1 = enable

Example:

>SXASMM1<

Set with Buffer: >SXASMM{mode}0{size}<

Enable modem mode with specified buffer size using reserved byte 0.

• {mode}: 0 = disable, 1 = enable
• 0: Reserved byte (must be literal 0)
• {size}: Buffer size in bytes (4 digits, 0100–9999)

Example:

>SXASMM101024<  (enable with 1024-byte buffer)

XASMS — Satcom State

Query the satellite modem connection state, signal strength, IMEI, and message status.

Query: >QXASMS<

Response (Disconnected): >RXASMS0<

Response (Connected): >RXASMS{conn}{signal}{imei}{msg_state}{err_code}<

• {conn}: Connection state (0 = disconnected, 1 = connected)
• {signal}: Signal strength (1 digit: 0–5)
• {imei}: IMEI number (15 hex digits)
• {msg_state}: Last message result state (1 digit)
• {err_code}: Error sending message code (2 digits: 00–99)

XASMS Status / Error Codes

msg_state (D) possible values:

D	Meaning
0	Success
1	Initial delimiter error
2	Final delimiter error
3	Checksum error
4	Length error
5	Busy
6	No network coverage
7	Error sending message

err_code (EE) values:

EE	Meaning
00-99	Modem/provider-specific error code associated with the last send attempt

Example (Disconnected):

>QXASMS<
>RXASMS0<

Example (Connected):

>QXASMS<
>RXASMS13300112233445566778899AABBCC1210<

Integration

SATCOM mode disables the serial console. To exit SATCOM mode and return to console mode:

1. Via TAIP Command: Send >SXASMM0< to disable modem mode
2. Via Serial Escape: Send EXIT_COMMDATA as a single packet to escape SATCOM communication

Once SATCOM mode is enabled, it is retained after reset and power cycle.

Wiring Notes (Reference)

The SATCOM accessory uses a DB9 serial connector to interface with the device serial port.

Common wiring signals in the reference accessory:

Wire	Description
Green	Main power (8V-32V)
Black	GND
Blue/Red	TX from SATCOM
White/Orange	RX from SATCOM

Related Features

• Serial Modem Mode — Operates in dedicated SATCOM mode when enabled
• Message Queuing — Automatic retry on transmission failure

Specifications

Parameter	Range	Default
Buffer Size	100–9999 bytes	560 bytes
Signal Strength	0–5	(device-dependent)

Troubleshooting

Issue	Cause	Solution
No SATCOM connection	Modem not enabled or disabled	Enable with >SXASMM1<
Signal strength = 0	Poor satellite visibility	Move to open area with clear sky view
High error codes	Message transmission failure	Check modem buffer size; may need to increase with >SXASMM10{size}<