4601 I-V Meter Operation Manual
6.4 Status Register Structure
6-10
The 4601 has the following four types of status registers:
•
Status Byte Register (STB)
•
Standard Event Status Register (SESR)
•
Questionable Event Register (QSR)
•
Measurement Event Register (MER)
1. Statue Byte Register (STB)
Table 6-3 Status Byte Register
bit
Name
Description
0
MSB
(Measurement Summary
Bit)
ON: Set to 1 when any of Measurement Event Register events occurs and the
bit is set to 1, if the corresponding bit of Measurement Event Enable
Register is also 1.
OFF: Set to 0 when Measurement Event Register is cleared by being read.
1
Not in use
Always set to 0
2
EAV
(Error Available)
ON: Set to 1 when error information is stored in Error Queue.
OFF: Set to 0 when Error Queue is read and becomes empty.
3
QSB
(Questionable Summary
Bit)
ON: Set to 1 when any of Questionable Event Register events occurs and the
bit is set to 1, if the corresponding bit of Questionable Event Enable
Register is also 1.
OFF: Set to 0 when Questionable Event Register is cleared by being read.
4
MAV
(Message Available)
ON: Set to 1 when the output data is entered in the output buffer.
OFF: Set to 0 when the output buffer is read and becomes empty.
5
ESB
(Standard Event Status)
ON: Set to 1 when any of SESR events occurs and the bit is set to 1, if the
corresponding SESER bit is also 1.
OFF: Set to 0 when SESR is cleared by being read (*ESR?).
6
MSS
(Master Summary)
ON: Set to 1 when any of STB events occurs, if the corresponding SRER bit
is 1.
RQS
(Request Service)
ON: Set to 1 when MSS is set to 1, and SRQ is generated.
OFF: Set to 0 when STB is read by a serial poll.
7
Not in use
Always set to 0
