KEPCO MST 488 Programmer - Manual (Page 41)

MST488-27 013004
3-15
Questionable register for the selected channel. The contents of the STATus Questionable regis-
ter can also contain the summary of all instruments as shown in Figure 3-5.
The selection of the status reporting structure is controlled by the
SYStem:SET SI
(Instrument
Structure) command, either
SI0
(off) or
SI1
(on). The power-up default is the off condition. To
enable the SCPI compliant mode of operation for multiple logical instruments the user must
send
SYSTem:SET SI1
to the MST 488-27 during initialization. The
SI1
state is not remem-
bered when the unit is turned off. To return to the standard method of reporting the selected
device’s status without turning the unit off, send
SYSTem:SET SI0
.The state of the power
power supply upon power up for language (SCPI/CIIL), compatibility and GPIB addressing is
selected by DIP switches P1 and P2 (see PAR. 2.2.2 and Table 2-2).
When the MST 488-27 is set up for SCPI compliant status reporting for multiple channels, the
specific instrument’s Questionable register is found in the STAT:QUES:INST:ISUM register.
This register has the same bit structure as the single channel Questionable register. The ISUM
enable register is ANDed with the bits of the channel’s ISUM register and its bit is placed in the
INST register. The Questionable register bits are the logical ORing of all channels’ Questionable
ISUM register. This is shown in Figure 3-5.
The ISUMmary registers set the INSTrument register, which in turn sets bit 13 of the QUEStion-
able or OPERation status register. This is shown pictorially in Figure 3-5.
The STATUS:QUESTIONABLE and STATUS:QUESTIONABLE:CONDITION registers are the
same in this mode of status reporting. The condition register indicates the status of the various
event registers and bits set are only cleared if the source of the bit is cleared.
FIGURE 3-5. EXPANSION OF QUESTIONABLE REGISTER FOR MULTIPLE LOGICAL INSTRUMENTS