BIT 4886 051010
4-1
SECTION 4 - OPERATION
4.1
GENERAL
The Kepco BOP Power Supply, with an installed BIT 4886 Interface Card, may be programmed
over the IEEE 488 standard communication bus (General Purpose Interface Bus, GPIB) using
SCPI (Standard Commands for Programmable Instruments). SCPI provides a common lan-
guage used in an automatic test system. (Refer to Table 2-3 for input/output signal allocations.)
CAUTION: DO NOT repeatedly toggle the circuit breaker/switch as this may cause unit to fault.
Set Power ON/OFF circuit breaker/switch on front panel to ON. If actuator does not
lock when released, wait a few seconds before trying again. The circuit breaker is
“trip-free” design; if overload exists, contacts cannot be held closed by actuator.
NOTE: Upon power up, the BOP output is set to off, VOLTage and CURRent are set to 0.
VOLTage and CURRent commands will not change the BOP output until the command
OUTPut ON is sent to the BIT 4886.
4.1.1
PROGRAMMING TECHNIQUES TO OPTIMIZE POWER SUPPLY PERFORMANCE
Proper programming techniques can offer significant response time improvement and reduce
undesirable transients at the power supply output. The key to performance optimization is to
minimize mode changes (voltage mode/current limit to current mode/voltage limit or vice versa).
Mode changes should be limited to changes in load conditions (to which the power supply will
respond automatically), or by programming the limit parameter when required by the user appli-
cation.
The proper way to program the power supply is to initially program the operating parameter to
zero and the complementary limit parameter to the desired maximum value. Subsequent com-
mands should change only the operating parameter. (The operating parameter is the parameter
that controls the output, e.g., voltage controls the output in voltage mode, current in current
mode.) The complementary limit parameter should be programmed only when there is a need to
change it.
4.1.1.1
EXAMPLE OF PROPER PROGRAMMING
Assume the power supply is intended to operate in a test application that requires a set of spe-
cific output voltages. The initial set of commands should program output voltage and current
limit. If the same current limit applies to the rest of the test, all subsequent commands should
only program output voltage.
4.1.1.2
MAKING SURE THE PREVIOUS COMMAND IS COMPLETE
Some SCPI commands require a flash memory update and can take an indeterminate amount
on time to complete. These commands are:
• *SAV
• MEM:PACK
• MEM:UPD
• CAL:COPY
• CAL:SAVE
• SYST:PASS:NEW
• SYST:SEC:IMM
