S p e z i a l e l e k t r o n i k G m b H
iseg Spezialelektronik GmbH
Email: [email protected]
Tel ++ 49 (0) 351 / 26 996 - 0
Bautzner Landstr. 23
http://www.iseg-hv.de
Fax ++ 49 (0) 351 / 26 996 - 21
D - 01454 Radeberg / Rossendorf
5
5.2 RS-232- / USB Interface
Attention:
Turn off the device with mains switch POWER before connecting/disconnecting
the interface cable.
Attention:
If you device is equipped with RS-232 and USB Interface, only one of them must
be connected to the HPS at the same time.
RS-232
The RS-232 interface is located at a female D-SUB-9 connector at the device rear.
The electrical transfer is working indirectly coupled via RxD and TxD related to GND. The D-SUB-9
pin assignment is in the following table.
The cable connection to the computer is 1:1 (no zero modem-cable!). If no 9-pole cable is available,
then the connections shown in the table have to be made.
Signal
HV-PS
PC
Connection
RS-232
D-SUB-9
Internal
D-SUB-9
D-SUB-25
3-pol. cable
RxD
2
2
3
TxD
3
3
2
GND
5
5
7
4
─┐
4
20
─┐
6
─┤
6
6
─┤
8
─┘
8
5
─┘
USB
The USB interface is realized with a female USB-B connector at the device rear. Internal, the USB is
implemented as an USB-serial converter FTDI FT232R.
This device functions as virtual serial port in PC, and thus can be used with every program that sup-
ports a serial port, e. g. a terminal program or LabVIEW.
Programming
The following description applies both to RS-232 and USB interface.
For remote control, “RS-232” must be selected in Menu “F07 Set Interfce“. The device switches to
REMOTE state when receiving the first command via interface.
The (virtual) serial Interface is set to 9600 Bit/s, 8 Bit/character, no parity, 1 Stop-Bit.
The data transfer is character oriented, while the synchronization in direction "Computer to HV PS
unit” (Input direction) is made by echoes. The transfer direction “HV-PS to computer“ (Output direc-
tion) is free running.
The Echo can be permanently disabled (Factory setting is “Echo on“):
1. On front panel via Menu “F11 Set Echo“.
2. Via SCPI instruction set with EDCP
The command transfer works with ASCII code. Commands are terminated by <CR><LF> ($0D $0A
or 13 10). On input side, no leading zeros are needed. Output is fixed format without leading zero.
A minimum time delay of 20 ms between write and read instructions is needed.
