NAL RESEARCH CORPORATION A3LA-R, Руководство пользователя

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A3LA-R-MIL-MOD User Guide Version B
Document Number: 451-93156-001A 83 of 159

The <SBD message length> parameter represents the length, in bytes, of the
SBD message not including the mandatory two-byte checksum.

The maximum mobile originated SBD message length is 1960 bytes. The
minimum mobile originated SBD message length is 1 byte.

Once the Dte receives the READY indication from the A3LA-R, the SBD message
must be sent from the DTE formatted as follows:
{binary SBD message} + {2-byte checksum}
o
The checksum is the least significant 2-bytes of the summation of
the entire SBD message. The high order byte must be sent first. For
example if the DTE were to send the word “hello” encoded in ASCII
to the A3LA-R the binary stream would be hex 68 65 6c 6c 6f 02 14.
o
The mobile originated buffer will be empty upon power-up.

If any data is currently in the mobile originated buffer, it will be overwritten.
Command Response:
0: SBD message successfully written to the A3LA-R.
1: SBD message write timeout. An insufficient number of bytes were
transferred to the A3LA-R during the transfer period of 60 seconds.
2: SBD message checksum sent from DTE does not match the checksum
calculated at the A3LA-R.
3: SBD message size is not correct. The maximum mobile originated SBD
message length is 1960 bytes. The minimum mobile originated SBD
message length is 1 byte.
B.86 +SBDRB – S
HORT
B
URST
D
ATA
: R
EAD
B
INARY
D
ATA
Exec Command: +SBDRB
This command is used to transfer a binary SBD message from the single mobile
terminated buffer in the A3LA-R to the DTE. The mobile terminated buffer can contain
only one message at any one time.

The SBD message is transferred formatted as follows:
{2-byte message length} + {binary SBD message} + {2-byte checksum}