User manual

Publication AG-UM008C-EN-P - February 2005
Basic DF1 Protocol Troubleshooting B-7
DF1 Radio Modem Protocol
To help you diagnose communication problems, you can use a serial
line analyzer to see the data packets being transmitted on the RS-232
link between the DTE and the DCE. For further details, see the DF1
Protocol and Command Set Reference Manual, publication
1770-RM516.
Table B.5 Summary DF1 Radio Modem Protocol Packet Exchanges
Table B.6 Identify the DF1 Radio Modem Packets
See ANSI X3.4, CCITT V.3, or ISO 646 for the standard definition of
these characters.
For the See
different types of communication packet
exchanges between two radio modem stations
Table B.5
definitions of the packets Table B.6
Message Type Sender Station’s Packet Receiver Station’s Packet
Sender station transmits a MSG instruction to a receiving
station; receiver station replies
DLE STX message DLE ETX BCC/CRC DLE STX reply DLE ETX
BCC/CRC
Sender station transmitting a MSG instruction to a receiver
station; receiver station cannot receive the message or error in
transmission - packet dropped, no reply
DLE STX message DLE ETX BCC/CRC none
Symbol Hexadecimal Binary Type Meaning
DLE STX 10 02 0001 0000 0000 0010 control symbol Start of header
Sender symbol that indicates the start of a
message
DLE ETX BCC/CRC 10 03 xx(xx) 0001 0000 0000 0011 control symbol Sender symbol that terminates a message
DLE DLE 10 10 0001 0000 0001 0000 data symbol Represents the data value of 10 (hex)
APP DATA application specific data symbol Single characters having values 00-0F and 11-FF
Includes data from the application layer
including user programs and common
application routines