KEPCO KLP Series Developers Guide, Rev 3 - Manual (Page 117)

KLP 041213
B-11
B.41 [SOURce:]CURRent:MODE? QUERY
CURR:MODE?
Syntax: Short Form: [SOUR:]CURR:MODE? Long Form: [SOURce:]CURRent:MODE?
Return value: FIXED or LIST or TRAN
Description: Identifies active voltage mode. Returns LIST while list is being executed. TRAN (transient) is not
supported at this time, contact Kepco for more information. Returns FIXED while in fixed (default)
mode of operation. Related Commands: LIST commands. (See example, Figure B-2.)
B.42 [SOURce:]CURRent:PROTection[:LEVel] COMMAND
CURR:PROT
Syntax: Short Form: [SOUR:]CURR:PROT[:LEV]
Long Form: [SOURce:]CURRent:PROTection[:LEVel]
= digits with decimal point and Exponent, e.g., 2.71E+1 for 27.1
Description: Sets overcurrent protection (OCP) level for power supply. Restricts valid programmable current to
be no greater than 80% of this setting, overriding virtual model current limit (CURR:LIM:HIGH) when
overcurrent protection is less than 80% of than the current limit. Valid range for CURR:PROT setting is
72% to 120% of rated model maximum current (e.g., 23.98 to 39.96A for KLP 75-33).
After executing CURR:PROT, the Output is set to OFF and previously stored trigger levels are
reset to zero volts and minimum current.
If the programmed OCP value is out of the acceptable overcurrent range for the power supply
model, error message -222,”Data out of range” is posted in the output queue. If the power supply out-
put exceeds the current protection level programmed, then the power supply output is disabled (pro-
grammed to 0V, minimum current) and the OCP bit in the Questionable Condition status register is
set. The value of CURR:PROT is automatically recalculated if CURR:LIM:HIGH is executed. (See
example, Figure B-4.)
FIGURE B-4. PROGRAMMING AS A CURRENT STABILIZER
NOTE: The following example assumes KLP 75-33-1200 with virtual model set for 36V, 33.33A and output
operating in current stabilization mode. See Figure B-3 for directions on programming virtual
model limits.
VOLT 32.1;CURR 4 Programs output voltage for 32.1V, output current for 4A.
OUTP ON Enables output. NOTE: Load determines output operating mode; if
load resistance is less than 32.1V/4A = 8.025 Ohms, output will
operate as current stabilizer.
MEAS:CURR? Returns measured output current, approximately 4E0 assuming cur-
rent stabilizer operation.
CURR? Returns 4E0 (4A, programmed output current).
CURR 3.3E-1 Programs output current to 0.33A. NOTE: For this model, 0.4A is the
minimum load current, therefore although 0.33 value is programmed;
load current will not be less than 0.4A. No explicit indication is given
regarding this change.
CURR? Returns 4E-1 (0.4A).
CURR? MAX Returns 3.333E1 (33.33A, the virtual model current setting).
CURR:PROT .5 For this model, minimum overcurrent protection is 0.72 x 33.33 = 24A,
therefore power supply returns error message -222 (Data out of
range, ESR bit 4 =1) and the limit remains unchanged.
CURR:PROT 25 Programs overcurrent protection limit to 25A.
CURR:PROT? Returns 2.5E1 (25A).
CURR 26 Returns error message -301 (Value bigger than limit, ESR bit 3=1) and
current setting remains unchanged at 0.4A.
CURR:PROT?MAX Returns 4E1 (maximum allowable overcurrent protection limit for
model is 40A, 20% above maximum current (33.33A) for KLP 75-33-
1200, regardless of virtual model setting).