Rs 232 Communication Descriptions - Varian Turbo-V 70 Bedienungshandbuch

RS 232 Communication Descriptions

Communication format:
•
8 data bit
•
no parity
•
2 stop bit
•
The baud rate is programmable via front panel from
600 to 9600 baud. The controller is factory-set for
9600 baud operation.
When a baud rate of 2400, 4800, 9600 baud is used,
the requested information from Host to controller must
be sent with a minimum interval of 1 second to avoid
the controller hang-up.
Communication protocol:
Host = Master
Turbo-V 70 Controller = Slave
The communication is performed in the following way:
Host
Request is an ASCII character identifying the action that
must be performed by the controller or the requested
information.
Allowed ASCII characters:
•
"A" = START
•
"B" = STOP
•
"C" = Low Speed ON
•
"D" = Low Speed OFF
•
"E" = Request for operational parameters
•
"F" = Pump times zeroing
•
"G" = Parameters reading
•
"H" = Parameters writing
•
"I" = Request for operating status
•
"J" = Request for numerical reading
•
"K" = Request for counters reading.
CRC corresponds to the sum (with inverted sign) of all the
preceding bytes.
e.g., the START command "A" in ASCII
inverted it will be: FF + 1 - 41 = BF.
NOTE
Turbo-V 70 Controller
code = 41;
CHARACTER ASCII
"A"
CRC
"B"
CRC
"C"
CRC
"D"
CRC
"E"
CRC
"F"
CRC
"G"
CRC
"H"
"I "
CRC
"J"
CRC
"K"
CRC
"ACK"
CRC
"NACK"
CRC
Answer = after a request from the host, the
Turbo-V 70 controller will answer in one of the following
ways:
•
ACK
•
NACK
•
Message
When the Request is "A, "B", "C", "D", "F", the Turbo-V 70
controller will Answer the ACK or NACK.
55
TECHNICAL INFORMATION
CONVERTED ASCII
FOR CRC CALCULATION
41h -
- BFh
42h -
- BEh
43h -
- BDh
44h -
- BCh
45h -
- BBh
46h -
- BAh
47h -
- B9h
48h -
49h -
- B7h
4Ah -
- B6h
4Bh -
- B5h
06h -
- FAh
15h -
- EBh
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