Rs 485 Communication Description; Transmission Channel Characteristics; Message Structure - Varian Turbo-V 550 Mode D'emploi

When the Request is "K" (Counters readings), the
Answer will contain a string of 11 characters with the
following parameters:
Bytes
1-4 Cycle time
5-8 Pump life
9-10 Cycle number
11 CRC
When the Request is "L" (software version), the Answer
will contain a string of 12 characters with the following
parameters:
Bytes
1-3 Software version
4-7 CRC 16 EPROM
8-11 CRC 16 parameters
12 CRC
On request a sample program in QBasic language is
available by Varian.
When the configuration parameters have to be changed,
send a Request string with the letter "S" and a series of
characters as shown below:
"S" + .... DATA .... + CRC
The CRC is calculated on the string consisting of
S + DATA.
This field is structured as follows:
Bytes
1
0 ÷ 4
2 CRC
The values assumed by byte "1" have the following
meaning:
0 = 600 baud
•
1 = 1200 baud
•
2 = 2400 baud
•
3 = 4800 baud
•
4 = 9600 baud
•
Meaning
Meaning
Meaning

RS 485 Communication Description

Communication RS 485 serial port connections

Transmission Channel Characteristics

levels:
baud rate:
character length:
parity:
stop bit:
protocoll:
max. devices:

Message Structure

(request and answer have the same format)
The master system (PC) starts every session sending
the following message to the slave units connected:
<STX> / <ADDR> + <WINDOW> + <COMMAND> +
<DATA> + <ETX> + <CRC>
where:
<STX>=
<ADDR> =
<ADDR> =
<WINDOWS>=
<COMMAND>=
59
TECHNICAL INFORMATION
RS 485
9600/4800/2400/1200/600
programmable
8 bits
none
1 bit
master (PC) / slave (converter)
32
0x02
0x80 (for RS 232 and
RS 422 only)
0x80 + device number (0...31)
0xFF: brodcasting command
(recognized by all the devices, it
doesn't implicate any answer)
(for RS 485 only)
' 000 '...' 999' window number
the meaning of the window
depends to the device type
0x30: window value reading
0x31: window writing
87-900-885-01 (B)