KEPCO BOP 1KW-MG Operator Manual, Firmware Ver.3.05 to 4.07 - Manual (Page 108)

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BOP HIPWR 031912
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.
3.5.2.2 MAKING SURE THE PREVIOUS COMMAND IS COMPLETE
Some SCPI commands require a flash memory update and can take an indeterminate amount
of time to complete. These commands are:
• *SAV
• MEM:PACK
• MEM:UPD
• CAL:COPY
• CAL:SAVE
• SYST:PASS:NEW
• SYST:SEC:IMM
When sending these commands via the GPIB, these commands require a query to be added to
the command string to verify the previous command is complete. When the command is com-
plete, the unit updates the status byte and indicates MAV (Message Available, bit 4 - see Table
A-3) is true. MAV indicates that there is a response to be received by the computer, so when it
becomes set, the unit is ready for its next command after reading back the data from the query
that was added to the command string.
When sending the above commands via the RS 232 bus, data flow control must be enabled
(XON) for the unit to properly update flash memory.
The *OPC? query is ideal to check if the previous command is complete since it returns either a
1 or 0. It is important that it be sent as a part of the same string as the command that causes a
flash update. As an example, sending CAL:SAVE 12/31/2005;:*opc? or *opc?;:CAL:SAVE
12/31/2005 are valid command strings. Sensing the commands separately will not verify that the
previous command is complete. Figure 3-16 is a program written in C, incorporating these tech-
niques.
Failure to provide an adequate delay can result in:
• Commands that are not processed,
• The following command may be received in error, causing an error in the transmission,
• Unit lock-up requiring power cycling of the unit. If working via the GPIB bus, sending
Interface Clear and Device Clear followed by *RST will unlock the unit.