KEPCO KLP Series Developer's Guide, Rev 1 - Manual (Page 117)

KLP 031113
B-11
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 at least 20% less than this setting, overriding virtual model current limit (CURR:LIM:HIGH) when
overcurrent protection is less than 20% higher than the current limit.
After executing CURR:PROT, the Output is set to
OFF. Previously stored trigger levels are reset to zero volts and minimum current.
If the 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 output exceeds the current protection level programmed, then the power supply out-
put is disabled (programmed to 0V, minimum current and the OCP bit in the Questionable Condition
status register is set. This value is automatically recalculated if CURR:LIM:HIGH is executed. (See
example, Figure B-4.)
B.43 [SOURce:]CURRent:PROTection[:LEVel]? QUERY
CURR:PROT?
Syntax: Short Form: [SOUR:]CURR:PROT[:LEV]? {MIN | MAX}
Long Form: [SOURce:]CURRent:PROTection[:LEVel]? {MIN | MAX}
Return Value: = digits with decimal point and Exponent, e.g., 2.71E+1 for 27.1
Description: Returns value representing current protection level.CURR:PROT? returns value set by
CURR:PROT. CURR:PROT?MAX returns maximum current protection value. This value is deter-
mined at the factory and cannot be changed by the user. CURR:PROT?MIN returns the minimum cur-
rent protection value. (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).