3 - Programming the DC Source
Programming the Status Registers
You can use status register programming to determine the operating condition of the dc source at any
time. For example, you may program the dc source to generate an interrupt (assert SRQ) when an event
such as a current limit occurs. When the interrupt occurs, your program can then act on the event in the
appropriate fashion.
Figure 3-7 shows the status register structure of the dc source. Table 3-1 defines the status bits. The
Standard Event, Status Byte, and Service Request Enable registers and the Output Queue perform
standard GPIB functions as defined in the IEEE 488.2 Standard Digital Interface for Programmable
Instrumentation. The Operation Status and Questionable Status registers implement functions that are
specific to the dc source.
Power-On Conditions
Refer to the *RST command description in chapter 4 for the power-on conditions of the status registers.
QUESTIONABLE STATUS
CONDITION
PTR/NTR
0
OV
1
1
1
OCP
2
2
2
FS
4
4
3
N.U.
4
OT
16
16
5-8
N.U.
9
RI
512
512
10
Unreg
1024
1024
11-13
N.U.
14
MeasOvld
16384
16384
15
N.U.
STANDARD EVENT STATUS
EVENT
ENABLE
0
1
1
OPC
1
N.U.
2
4
4
QYE
3
8
8
DDE
4
16
16
EXE
5
32
32
CME
6
N.U.
7
128
128
PON
OPERATION STATUS
CONDITION
PTR/NTR
0
CAL
1
1
1-4
N.U.
5
WTG
32
32
6,7
N.U.
8
CV
256
256
9
N.U.
512
512
10
1024
1024
CC+
11
CC-
2048
2048
12-15
N.U.
32
EVENT
ENABLE
1
1
2
2
4
4
16
16
512
512
1024
1024
16384
16384
OUTPUT QUEUE
QUEUE
DATA
DATA
DATA
EVENT
ENABLE
1
1
32
32
256
256
512
512
1024
1024
2048
2048
Figure 3-7. DC Source Status Model
OFF
N.U.
0-2
QUES
3
NOT
EMPTY
MAV
4
ESB
5
MSS
6
OPER
7
SERVICE
REQUEST
STATUS BYTE
ENABLE
8
8
16
16
32
32
64
128
128
RQS
SERVICE
REQUEST
GENERATION
FI G4- 6. GAL
FLT