M9B-HFS INTERFACE
M9B-HFS OPERATION
Release 1.0 (97/10)
3-13
3.4 Accumulated Status, Status, and Fault Registers
The HFS-M9B option card uses three separate registers which are always active. They are the accumulated
status, status, and fault registers. You can use the status commands shown in Table 3.2-4 to activate the
registers. The bit register has twelve conditions, each assigned a bit weight. When querying a register, the
controller returns a response which is the sum of the weights of all relevant conditions.
Example:
ASTS?
Queries the accumulated status register.
ASTS
771
Controller Response
771 = 512 + 256 + 2 + 1 = PON + REM + CC + CV
The accumulated status register shows that PON, REM, CC, and CV have all been active since the last
accumulated register query.
Table 3.4-1 shows the mnemonics and bit weights which correspond to each register condition. You can select
conditions you want to monitor in the fault and status register by using the MASK and UNMASK commands.
Table 3.4-1 Accumulated Status, Status, and Fault Registers
Condition
Mnemonic
Bit Position
Bit
Weight
Constant voltage operation
CV
0
1
Constant current operation
CC
1
2
Not used
–
2
4
Over voltage protection tripped
OV
3
8
Over temperature protection tripped
OTP
4
16
Supply external shutdown active (J7-1)
SD
5
32
Foldback mode operation
FOLD
6
64
Remote programming error
ERR
7
128
Power ON (accumulated status, status registers only)
PON
8
256
Remote mode (accumulated status, status registers only)
REM
9
512
AC fail condition
ACF
10
1024
Output fail condition
OPF
11
2048
Sense protection tripped
SNSP
12
4096
Notes:
1. All mnemonics can be masked or unmasked.
2. The error (ERR) bit is reset in the status registers with an error query (ERR?).
3. The accumulated status register is cleared with an accumulated status query (ASTS?).
4. A fault is cleared with a fault query (FAULT?).
