KEPCO BHK-MG 40W (Half Rack) Series - Manual (Page 60)

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BHK-1/2-MG 121313
To change the DCL mode the unit must be in command entry mode
(:_:_:)
, then depress the
MENU key until the top line of the display shows the current setting: either
DCL OUTP = 0
or
DCL = OUTP UNCHNG
. Depress 1 for “output unchanged” mode where the output is unaffected
by DCL; depress 1 again for “output = 0” mode where DCL sets the output to 0 volts and current
is set to the power-up and reset current value (see PAR. 3.2.8.1).
3.3.3 CHANGING THE GPIB ADDRESS
When the power supply is in command entry status
(:_:_:)
, press MENU key until the top line
of the LCD displays
GPIB addr. = nn
where
nn
indicates the current GPIB address. Enter
new value and press ENTER to accept new setting, or CLEAR to exit without changing setting.
The GPIB address default value is set to 6.
3.3.4 EXTERNAL TRIGGER
The External Trigger Port can be used to restore the power supply output to settings previously
defined using SCPI commands. This can be done by applying a temporary short between pin 4
and pin 1 of the External Trigger Port, (or if pin 4 is at TTL logic 1, applying a temporary logic 0
to pin 4 referenced to pin 1).
NOTE: Turn off power to the unit or disable the output before inserting the plug in the External
Trigger port to avoid unintentionally initiating shutdown or trigger.
The following remote SCPI commands must be sent before the external trigger at pin 4 acti-
vated:
• The values to be set upon receiving the external trigger at pin 4 must be programmed
using VOLT:TRIG (PAR B.56) and CURR:TRIG (PAR B.46) commands.
• Choose external trigger source by sending TRIG:SOUR EXT (PAR. B.90)
• Choose continuous action (by sending INIT:CONT ON (PAR B.12).
NOTE: The output must be enabled prior to activating the external trigger at pin 4 of the External
Trigger port in order for the external trigger to work properly.
3.3.5 PROGRAMMING TECHNIQUES TO OPTIMIZE PERFORMANCE
3.3.5.1 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 enters the mode of operation, constant voltage (CV) or constant current (CC)
determined by the power supply settings and load value. Reducing the number of times that the
unit changes mode from CV to CC or from CC to CV 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 time while the two feedback loops compete for
control of the output. By changing only the active parameter (e.g., voltage for voltage mode) and
leaving the inactive parameter (e.g., current in this case) set to a value higher than the maxi-
mum imposed by the load, the response is quick and no transients are possible. Recommended
programming techniques are: