7 USB interface
The computer interface allows to control all relevant parameters of the high voltage source. Up to three high voltage channels
can be controlled over one computer interface. The USB interface is realized with a female USB-B connector (Figure 19) at the
device rear ( Figure 3: Rear panel with AIO and USB connectors). Internal, the USB is implemented with an USB-serial converter
. This device functions as virtual serial port in PC, and thus can be used with every program that supports a serial
port, e. g. a terminal program or
The data exchange is character-orientated, with echo in direction “computer to HV source”. The direction “HV source to computer
(answer)” is free-running.
The hardware settings of the virtual serial interface are:
•
9600 bit/s
•
8 bit/character
•
no parity
•
1 stop bit.
No flow control (handshake) is used.
When using the HV source via computer interface, the following functions are possible:
1.
write functions:
•
Set Nominal voltage
•
Set Nominal current
•
Set Polarity (EPU)
•
Set Interface active after restart
2.
reading functions:
•
Set Target voltage
•
Set Actual voltage
•
Set Target current
•
Set Actual current
•
Set Polarity
•
Set Status
•
Set Identifier
•
Set Interface active after restart
When operating in local or analogue I/O mode, the read functions are possible via computer interface.
When setting a voltage value over interface (command D#
), the device switches to mode computer control.
The command transfer uses ASCII characters. Every command line is terminated by <CR><LF> (0x0D 0x0A or 13 10).
A new command may be sent immediately after the last answer was completely received (including <CR><LF>).
4
© National Instruments Corporation. All rights reserved.
5
# number of channels (1, 2 or 3)
THQ Systems - CONFIGURABLE AC/DC LABORATORY HV SUPPLY | Last modified on: 2022-04-21 | www.iseg-hv.com
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