Radyne DMD20 Installation And Operation Manual page 104

User Interfaces
<SYNC>:
<BYTE COUNT>:
<SOURCE ID>:
<DEST. ID>:
<FSN>:
<OPCODE>:
<...DATA...>:
<CHECKSUM>:
The Modem RLLP is not software-compatible with the following previous
Radyne products:
occupy the same bus while using this protocol as equipment malfunction
and loss of data may occur.
NOTE: When transmitting a packet at 9600 baud, the Remote M&C
should ensure that the timeout value between characters does not
exceed the time it takes to transmit 200 characters(≈ 200 msec). If this
timeout value is exceeded, the equipment will timeout.
4.9.3 DMD20 Opcode Command Set
Refer to Appendix B for Modem Remote Communications.
4-56
Message format header character that defines the
beginning of a message. The <SYNC> character value
is always 0x16 (1 byte).
The number of bytes in the <DATA> field (2 bytes).
Identifies the address of the equipment from where the
message originated (1 byte).
Identifies the address of the equipment where the
message is to be sent (1 byte).
Frame sequence number ensures correct packet
acknowledgment and data transfers (1 byte).
This byte identifies the message type associated with
the information data. The equipment processes the data
according to the value in this field. Return error codes
and acknowledgment are also included in this field (2
bytes).
Information data. The number of data bytes in this field
is indicated by the <BYTE COUNT> value.
The modulo 256 sum of all preceding message bytes
excluding the <SYNC> character (1 byte).
RCU5000 and DMD4500.
DMD20 Universal Satellite Modem
These products may not
TM103 - Rev. 1.1