124
About the Status Byte
The conditions from other status registers will be reported by the status byte summary register.
To clear an event register will clear the according bits in the status byte summary register. And
to read all messages in the output buffer, including all pending queries, will clear the message
available bit. The following list shows the definition of each bit.
Bit
Decimal
Value
Definition
0.
Not Used
1
Set to 0.
1.
Not Used
2
Set to 0.
2.
Not Used
4
Set to 0.
3.
Questionable Data
8
One or more bits are set in the questionable data register (Bits
have to be
“
enabled
”
in enable register).
4.
Message Available
16
Data in the DMM
’
s output buffer is available.
5.
Standard Event
32
One or more bits are set in the Standard Event Register (Bits have
to be
“
enabled
”
in enable register).
6.
Request Service
64
The DMM is requiring service (Serial Poll).
7.
Not Used
128
Set to 0.
On the other hand, there are some conditions that users have to note.