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11.2. Communication with a PC or a superordinated data system
If the recirculating cooler is put into remote control mode the MULTI-DISPLAY
(LED) will read „R -OFF-„ = REMOTE STOP. The recirculating cooler is now
operated via the computer.
In general, the computer (master) sends commands to the recirculating cooler
(slave). The recirculating cooler sends data (including error messages) only
when the computer sends a query.
)
In remote control mode:
After a power interruption the order to start and all values which have to be
adjusted must be resent from the personal computer via the interface.
AUTOSTART is not possible.
A transfer sequence consists of:
x
command
out/in command
x
space
(
; Hex: 20)
out/in command
x
parameter
(the character separating decimals in a group is the
period)
out command
x
end of file
(
; Hex: 0D) out/in command
x
The response (data string) after an
in
command is always followed by a
line feed (LF, Hex: 0A).
Important times for a command transmission:
¨
To ensure a safe data transfer, the time gap between two commands should
be at least 250 ms.
The recirculating cooler automatically responds to an
in
command with a data
string followed by a LF (Line Feed). The next command should only be sent
after 10 ms.
The commands are divided into
in
or
out
commands.
in
commands:
asking for parameters to be displayed
out
commands: setting
parameters
)
The
out
commands are valid only in remote control mode.
Examples:
Set the working temperature to15.5 °C:
out_sp_00
15.5
Ask for the working temperature
in_sp_00
Response from the recirculating cooler:
15.5
LF
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