KEPCO KLR Series User Manual - Manual (Page 83)

KLR 091313
4-5
NOTE: The limit model is always reset to the maximum model ratings (Eo
MAX
and Io
MAX
) fol-
lowing complete calibration.
4.4 CALIBRATION USING VXI plug&play DRIVER
Calibration of the KLR can be performed using SCPI commands implemented through the VXI
plug&play Instrument driver. The driver provides a graphical interface with informational dis-
plays and prompts which lead you through the calibration of the KLR. This VISA compliant
driver works with many GPIB cards from suppliers such as National Instruments and Hewlett-
Packard.
The following calibration procedure uses the “soft” front panel which is part of the VXI plug&play
driver for the KLR which can be downloaded from the Kepco website at: www.kepcopower.com/
drivers/.
Unzip the files and doubleclick on setup.exe to install the driver. The Kepco\klr folder will be
added to the Start - Programs folder. Doubleclick KLRCTRL.exe to run the program, and refer to
the KLR Developer’s Guide in the Kepco\KLR folder for details about using the soft front panel.
For voltage calibration all loads must be disconnected and the sense terminals connected to the
corresponding output terminals. The digital voltmeter will be connected to the output of the
power supply. For current calibration after disconnecting all loads an appropriate shunt resistor
will be connected across the output terminals and the digital voltmeter will be connected across
the sense terminals of the shunt resistor.
1. Turn off power supply and disconnect load from output bus bar at the rear of the unit.
2. Verify that power supply is configured for local error sensing (See PAR. 2.7.5.1) .
3. For voltage calibration connect DVM to (M+, S+) and (M–, S–) of terminal block at the rear of
power supply.
4. For current calibration connect an appropriate shunt resistor (see PAR 4.2) across the output
terminals and connect DVM to shunt resistor terminals.
5. Configure the mating I/O connector (provided with unit) to access the input programming sig-
nals (Vref and Cref) and output readback signals (VOLT_RBACK and CURR_RBACK) as
shown in Figure 4-1. Note that the wires to Vref and Cref should be tightly twisted with the
corresponding GND wire and kept as short as possible. Then connect the I/O mating con-
nector to the Analog I/O port of the power supply.
6. Turn on power supply, and after the status display shows SET, start the KLR VXI plug&play
demo program.
7. Click the Calibrate Access button on the VXI plug&play demo main panel: the button label
changes to Calibrate Close and the Calibration Window (Figure 4-2) opens with all buttons
disabled (grayed out) and PASSWORD appears in the text box near the top of the window.
The main panel status display shows calibration, and the voltage and current meters are not
visible.
8. Use the computer keyboard to enter the password in the text box displaying the word PASS-
WORD, then press the ENTER key.
9. If password is correct, the status display on the VXI main panel reads CAL and the buttons
on Calibration Screen (Figure 4-1) are enabled (highlighted). If the password is incorrect, the