Front Panel Menu Reference
SCPI Command
Select Protect\OCP
Enter a delay value. Then press Select.
By default, the delay timer will be started by an output
settings change.
Check "Start delay on CC" to start the delay timer by ANY
output transition into CL mode.
To specify a 10 millisecond delay:
To start the delay timer by an output settings change:
To start the delay timer by ANY output transition into CL
mode:
Factors that influence how long the output settings or load change may last include: difference
between old output value and new output value, the current limit setting, and the load capacitance in
CV mode or load inductance in CC mode. The delay required must be determined empirically; the
output programming-response time characteristics may be used as guidelines.
Also note that the time it takes the output to go into CL mode varies - depending on the magnitude of
the over-current condition compared to the current limit setting. For example, if the over-current is
only slightly greater than the current limit setting, it may take several tens of milliseconds for the
output to set the CC status bit. If the over-current is significantly greater than the current limit setting,
it may only take a few hundred microseconds or less for the output to set the CL status bit. To
determine when the output will shut down, you must add the time it takes for the CL status bit to the
over-current protection delay time. If the over-current persists beyond the sum of these two time
intervals, the output will shut down.
Output Watchdog Timer
When enabled, the output watchdog timer causes the output to go into protection mode if there is no
SCPI I/O activity on the remote interfaces (USB, LAN, GPIB) within the user-specified time period. Note
that the watchdog timer function is NOT reset by activity on the front panel – the output will still shut
down after the time period has elapsed.
After the time period has expired, the output will be disabled, but the programmed output state is not
changed. The Prot bit in the status questionable register as well as the Prot indicator on the front
panel will be set. A watchdog protect can be cleared as described under Clear Output Protection
Functions below.
The watchdog delay can be programmed from 1 to 3600 seconds in 1-second increments. To enable
the watchdog timer and specify a delay value, proceed as follows:
Front Panel Menu Reference
SCPI Command
Select Protect\WDog
Check Enable Watchdog to enable the watchdog timer.
Enter a value in the Watchdog Delay box. Then press
Select.
To enable the output watchdog timer:
To set the output watchdog timer to 120 seconds:
4 Using the Advanced Power System
114
Keysight N6900/N7900 Series Operating and Service Guide
Summary of Contents for N6900 Series
Page 1: ...Keysight Advanced Power System N6900 N7900 Series Operating and Service Guide...
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Page 63: ...1 kW Models Keysight N6900 N7900 Series Operating and Service Guide 63 1 Quick Reference...
Page 64: ...2 kW Models 1 Quick Reference 64 Keysight N6900 N7900 Series Operating and Service Guide...
Page 78: ...2 Installing the Instrument 78 Keysight N6900 N7900 Series Operating and Service Guide...
