National Instruments RMX-4120 User Manual page 141

Appendix B Troubleshooting
abnormal temperature, turn the power switch on. The air inlet may be clogged, or the fan may
be broken. Check them.
Is a shutdown (SD) signal being applied? Set pin 6 of the J1 connector to HIGH (4.5 to 5 V) or
open the pin, or eliminate the shutdown (SD) signal.
Unable to Set the Output Voltage or Output
Current Correctly
The output voltage cannot be set correctly.
Have you tried to specify a value that is higher than the OVP trip point? You cannot set the output
voltage to a value that is 95% of the OVP trip point or higher. Check the OVP trip point.
Have you tried to set a voltage value that is lower than the voltage value that is specified by
UVL? You cannot set the output voltage to a value that is lower than the voltage that is specified
by UVL. Check the voltage that is specified by UVL.
The output current cannot be set correctly.
Have you tried to specify a value that is higher than the OCP trip point? You cannot set the output
current to a value that is 95% of the OCP trip point or higher. Check the OCP trip point.
Output is Unstable
When the output is on, turning the VOLTAGE knob or CURRENT knob results in
unstable output.
Is the operation mode switching from CV to CC or CC to CV? Change the setting (output voltage
or output current) that is limiting the output to a value greater than the present setting. If the
setting is at maximum, you must use a power supply that has a larger output voltage or current.
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