Comtech EF Data CDD-562L - Manual (Page 221)

CDD-562L/564 Demodulator with IP Module Revision 2
Appendix D MN/CDD564L.IOM
D–5
D.3.4.1 Start of Packet
Controller-to-Target: This is the character '<' (ASCII code 60).
Target-to-Controller: This is the character '>' (ASCII code 62).
Because this is used to provide a reliable indication of the start of packet, these two characters may not appear anywhere else within the
body of the message. For multi line text message, each line should end with a new line character ‘\n’. The carriage return & new line [\r\n]
combination should present only at the end of the message.
D.3.4.2 Target Address
Up to 9,999 devices can be uniquely addressed. While any number of devices can be addressed, all devices should be associated with
single IP Address.
• For a CDM-570, an address of ‘1’ is being used to address both modulator and demodulator.
• For the CDD-564, each demodulator is identified by unique address, from 1 to 4 respectively, for all four demodulators.
The address is not significant for commands targeted system wide. But, it does has significance when associated with demod specific
commands like Frequency, data rate etc.
The Controller sends a packet with the address of a Target – the destination of the packet. When the Target responds,
the address used is the same address, to indicate to the Controller the source of the packet. The Controller does not
have its own address.
D.3.4.3 Address Delimiter
This is the character ‘/’ (forward slash) (ASCII code 47).
D.3.4.4 Instruction Code
This is a three-character alphabetic sequence that identifies the subject of the message. Wherever possible, the instruction codes have been
chosen to have some significance.