Multipoint Protocol - Unitech MR350 MKII Technical Reference Manual

The download command has one parameter, the file name. Download can
also be invoked via the MR350MKII workstation menu.
The upload command performs the opposite function of the download
command. It is normally used to transfer a data file from the MR350MKII to
the host system. This is the typical means of retrieving collected data in
workstation mode.
2. Upload ( ESC U filename )
When the MR350MKII receives an upload command it puts itself in file
transmission state and starts sending the designated data file. The file transfer
protocol is determined by a pre-assigned host protocol Kermit. The host
system waits for the arrival of the data file after it sends out the upload
command.
The upload command has one parameter, the file name. The upload
command can also be invoked via the MR350MKII workstation menu.
5.4.

Multipoint Protocol

In Multipoint operation the MR350MKII uses an asynchronous serial
multi-drop protocol for communication with the host computer. Note that to
make this protocol operable an RS-232 to RS-485 converter is needed
between the host and the MR350MKII. The terminal protocol consists of
commands and responses of the following format:
Symbol
=>
<=
ADDR Terminal address (A-Y,0-6) + 80H
CMD
CS1
CS2
The checksum is calculated by adding each byte of the transmission, ADDR,
and length of data block (excluding STX and ETX). CS1 is high nibble (4
bits) +40H and CS2 is low nibble +40H.
Example: Command to load the file named A.EXE
STX ESC L A . E X E CS1 CS2 ADDR
Data block
Description
Transmission from host to terminal
Transmission from terminal to host
Network command to terminal, 2 bytes, A-F,0-9
Checksum, first byte
Checksum, second byte
= ESC L A . E X E (excluding STX)
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