KEPCO ABC-DM SERIES - Manual (Page 44)

3-12
ABC 040104
ing, and local lockout). Refer to PAR. 3.7 for a detailed explanation of SCPI programming, and
to Appendix A and B for detailed explanations of IEEE 488 and SCPI commands, respectively.
3.4.1 DCL CONTROL
The device clear and selected device clear can be set to operate in two modes. In the “output =
0V” mode, when the device clear (DCL) is received, the output of the power supply is set to zero
volts. In the “output unchanged” mode sending DCL or selected DCL has no effect on output
voltage and current as required by IEEE specification 488.2; it only clears the GPIB program-
ming registers. The factory default value is “output unchanged” mode. NOTE: When set to “out-
put = 0V” mode, the power supply will power up with OUTPUT set to OFF.
To change the DCL mode the unit must be in command entry mode , then depress the MENU
key until the LCD shows the current setting: either
DCL sets OUTP=0V
or
DCL = OUTP
UNCHNG
. The bottom line of the display reads
depress 1 to toggle
. Depressing 1 toggles
the DCL mode and updates the displayed message. Depressing the RESET key leaves the
mode unchanged. Depressing 0, ENTER, or MENU updates the DCL mode and displays the
next selection.
3.5 IEEE 488 (GPIB) BUS OPERATION
This section includes a discussion of GPIB bus protocols (PAR. 3.5.1), instructions for changing
the GPIB address (PAR. 3.5.2), and a discussion of the VISA (Virtual Instrumentation Software
Architecture) driver (PAR. 3.5.3). Refer to PAR 3.3.8.1 for programming techniques to optimize
power supply performance. Refer to PAR. 3.7 for a detailed explanation of SCPI programming,
and to Appendix A and B for detailed explanations of IEEE 488 and SCPI commands, respec-
tively
3.5.1 IEEE 488 (GPIB) BUS PROTOCOL
Table 3-4 defines the interface capabilities of the ABC power supply (Talker/Listener) relative to
the IEEE 488 (GPIB) bus (reference document ANSI/IEEE Std 488: IEEE Standard Digital Inter-
face for Programmable Instrumentation) communicating with a Host Computer—Controller
(Talker/Listener). Tables 3-5 and 3-6 define the messages sent to the ABC, or received by the
ABC, via the IEEE 488 bus in IEEE 488 command mode and IEEE 488 data mode, respectively.
These messages are enabled during the “handshake” cycle, with the ABC power supply operat-
ing as either a Talker or a Listener.
3.5.2 CHANGING THE GPIB ADDRESS
When the power supply is in local mode, command entry status , press MENU until 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.