USER'S GUIDE Portable Data Terminals PT2000 and TopGun

Serial Parameters
User’s Guide 69
Xmodem is a simple send-and-wait-for-response protocol using a fixed-
length data field. The data field is embedded in an Xmodem packet,
which also contains a packet number and a single-byte arithmetic
checksum. The protocol link is established by the receiver transmitting a
NAK character until the sender responds. The sender responds by
transmitting an Xmodem packet. The sender then waits for either an
ACK signal, in which case it transmits the next packet, or a NAK signal,
in which case it retransmits the packet. Once all packets are transmitted,
the sender transmits an EOT signal, indicating the end of transmission.
Scan the following bar code to set a portable to use the Xmodem
protocol:
XModem
protocol
*$+$-CA02EE*
PT2000.book Page 69 Thursday, February 26, 2004 9:34 AM