KEPCO BOP-ME 1KW, Руководство оператора

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BOP HIPWR 091719
After initializing, the set point change (either VOLT or CURR) must be immediately followed by
*WAI. Note that *WAI has been modified to ensure that setpoint data is valid before executing
the next command in the string. To meet the 55 milliseconds (maximum) specification all com-
mands must be sent in a single commands string such as: CURR 4.80;:*WAI;:MEAS:CURR?
The MEAS:CURR command will return 4.80A within 55 milliseconds of sending the command
string. The 4.80A will be within the unit’s accuracy specifications (see Table 1-2) plus 10% of the
setpoint value, representing the short term stabilization error. In addition, MEAS? query has
been added to return both voltage and current measurements, followed by a status byte (see
Table B-2)
If the same commands are sent in two separate command strings, e.g, CURR 4.80;:*WAI fol-
lowed by MEAS:CURR?, the response time is 63 milliseconds maximum.
If the three commands (CURR 4.80, *WAI, MEAS:CURR?) are each sent separately, measure-
ment accuracy is still the same but response time is 100 milliseconds maximum. Each sepa-
rately sent *WAI will add 30 milliseconds to the processing delays.
3.5.2 PROGRAMMING TECHNIQUES TO OPTIMIZE PERFORMANCE
3.5.2.1 PROGRAMMING VOLTAGE/CURRENT LIMIT AND CURRENT/VOLTAGE LIMIT
Kepco's auto-crossover digital supplies can operate in either voltage mode with current limit, or
current mode with voltage limit. The operating mode is determined by the voltage and current
commands received, as well as the load. Each time voltage and current commands are
received, the unit must evaluate the commands and the load conditions to determine the neces-
sary operating mode. Reducing the number of times this evaluation must be made is desirable
because Kepco's digital auto-crossover supplies employ two separate feedback loops. Each
time there is a potential mode change, there is always an uncontrolled period of a few millisec-
onds while the two feedback loops compete for control of the output. By changing only the
active parameter (e.g., voltage for voltage mode), there is no doubt as to what the operating
mode will be, so the unit is never uncontrolled, response is quick and no transients are possible.
Recommended programming techniques are:
1. Minimize programmed mode (voltage or current) changes. Unless absolutely required by the
test parameters, allow the power supply to automatically switch modes as determined by the
load. This will improve response time and reduce undesirable transients.
2. Once the mode (voltage or current) is programmed, program the active parameter to zero
and the complementary limit parameter to the maximum anticipated for application. Then
program only the active parameter. The active parameter is the parameter that controls the
output, e.g., voltage controls the output in voltage mode.
3. Never program both the active and complementary limit parameter to zero. This can result in
long response times. Set the active parameter to zero and the complementary limit parame-
ter to a minimum, e.g., 10% of maximum, to ensure that the active mode is defined.