![background image](http://html1.mh-extra.com/html/varian/969-8988/969-8988_instruction-manual_854644021.webp)
TECHNICAL INFORMATION
79 87-900-986-01 (
C
)
The communication port mating connector is supplied
with the RS 232 PCB (AMP/Cannon or equivalent 15-
pin "D" type male connector).
For example, the Transmit data signal from controller
(pin 2) must be connected to the host computer's
receive data line (pin 2) and vice versa. Consult the
host computer's instruction manual for its serial port
connections.
NOTE
Varian cannot guarantee compliance with FCC
regulations for radiated emissions unless all external
wiring is shielded, with the shield being terminated to
the metal shroud on the 0-subconnector. The cable
should be secured to the connector with screws.
Serial Communication Descriptions
This unit can comunicate by two different protocol:
–
protocol (old system) “letter”
–
“Window” protocol (new system)
These two protocols can be used as well with 232 or
485 media.
NOTE
Please use “Window” protocol for new development.
LETTER PROTOCOL DESCRIPTION:
The default protocol is “Window”
Communication format:
•
8 data bit
•
no
parity
•
1 stop bit
•
The baud rate is programmable via front panel from
600 to 9600 baud. The controller is factory-set for
9600 baud operation.
Communication protocol:
Host = Master
Turbo-V 81-AG Controller = Slave
The communication is performed in the following way:
Host Turbo-V 81-AG Controller
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 code = 41;
inverted it will be: FF + 1 - 41 = BF.