National Instruments RMX-410 Series, User Manual

Page: 55 / 132

54
NATIONAL
INSTRUMENTS
CHAPTER 5: LOCAL OPERATION
5.1 Introduction
This Chapter describes the operating modes that do not require programming and monitoring the
power supply via its communication interface. USB or RS232/RS485 or by remote analog signals.
Ensure that the REM LED on the front panel is Off, (indicating Local mode). If the REM LED is On,
press the front panel REM button to change the operating mode to local.
- For information regarding remote analog programming refer to Chapter 6.
- For information regarding usage of the serial communication port refer to Chapter 7.
5.2 Standard Operation
The power supply has two basic operating modes: Constant Voltage mode and Constant Current
mode. The mode in which the power supply operates at any given time depends on the output
voltage setting, output current limit setting and the load resistance.
5.2.1 Constant Voltage Mode and Voltage Setting
1. In constant voltage mode, the power supply regulates the output voltage at the selected
value, while the load current varies as required by the load.
2. While the power supply operates in constant voltage mode, the CV LED on the front panel
illuminates.
3. Adjustment of the output voltage can be made when the power supply output is enabled
(Output On) or disabled (Output Off). When the output is enabled, simply rotate the Voltage
encoder knob to program the output voltage. When the output is disabled, press the PREV
button and then rotate the Voltage encoder to required value. The Voltage display will show
the programmed output voltage for 5 seconds. Then ”
OFF
” will appear on the Voltage display.
4. Resolution can be set to Coarse or Fine adjustment. Press FINE button to select between the
lower and higher resolution. The FINE LED illuminates when the resolution is set to Fine.
NOTE:
If after completing the adjustment, the display shows a different value than the setting, the power
supply may be at current limit. Check the load condition and the power supply current limit setting.
NOTE:
The maximum and minimum setting values of the output voltage are limited by the Over Voltage
protection and Under Voltage limit setting. Refer to sections 5.3.2 and 5.3.3 for more details.
5.2.2 Constant Current Mode and Current Setting
1. In constant current mode, the power supply regulates the output current at the selected value, while
the voltage varies with the load requirement.
2. While the power supply is operating in Constant Current mode, the CC LED illuminates.
3. Adjustment of the output current can be made when the power supply output is enabled
(Output On) or disabled (Output Off). When the output is enabled, simply rotate the Current
encoder knob to program the output current. When the output is disabled, press the PREV
button and then rotate the Current encoder to required value. The Current display will show
the programmed output current for 5 seconds. Then ”
OFF
” will appear on the Voltage display.
4. Resolution can be set to Coarse or Fine adjustment. Press the FINE button to select between the
Coarse and Fine adjustment. The FINE LED illuminates when the resolution is set to Fine.