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3. Communications protocol
The TR510E communications protocol is based on the GNET protocol
specification. The serial communications parameters are 19200-8-N-1. If your
PC software is through the serial port (RS232) to control the TR510E, you
may create virtual serial port by our supply software VSP manager (virtual
Serial Port manager). For easily connection PC software and TR510E by
RS232, the VSP manager (Virtual Serial Port manager) make connection
between Ethernet and virtual serial port which you created by VSP
manager. For detail description of VSP manager please see the manual of
“Quick Start Guide” .
Communications between the TR510E and the PC takes place in the form
of commands sent by the PC and replies from the TR510E. Commands and
replies are packets of data. Each packet begins with an STX (02H) character
and ends with CR (0DH) character. Selected commands and replies include a
checksum field as an additional safety measure. All characters between the
STX and the CR characters must be in the 20H...7FH range.
The STX character of a command packets is followed by a one-character
command code. The STX character of a reply packet is followed by a one-
character reply code. Both command and reply packets may contain some
relevant data after the command (reply) character:
STX
Cmd/Rpl
code
C1 C2 CR
02H Data (if any) Checksum* 0DH
*
Checksum field is not included into certain commands and replies
All available commands are described later in this Section. Of reply codes,
only two are possible: ‘A’ (completed successfully) and ‘N’ (some error was
encountered). Depending on the command given to the TR510E, reply packets
with reply code ‘A’ may contain some data (as shown on the Figure above).
Reply packets with the reply code ‘N’ always contain a 2-digit error code that
can be used to analyze the source of a problem.
The checksum is an 8-bit sum of all characters between the STX and CR,
represented as a 2-character HEX string. For an example packet below, the
checksum is calculated as follows. The data part of the packet is “A1XYZ”. The
sum of these character codes is: 41H+31H+58H+59H+5AH=17DH. Eight least
significant bits contain 7DH. The string representation of this value is “7D” (i.e. 2