Agilent Technologies Agilent E5250A - Manual (Page 219)

Agilent E5250A User’s Guide, Edition 11 7-51
Command Reference
Status Byte Register
In general, use serial polling (not *STB?) inside interrupt service routines. Use
*STB? in other cases (not in interrupt service routine) when you want to know the
value of Status Byte.
Table 7-1 Status Byte Register of E5250A
Bit Definition Explanation
0 Not Used. Always zero.
1 Not Used. Always zero.
2 Not Used. Always zero.
3 Not Used. Always zero.
4 Message Available
(MAV) Queue Summary
Message Indicates whether Output Queue is empty. If
unread message exists, this bit is set to 1.
Otherwise, this bit is set to 0. Refer to
“Output Queue” on page 7-55.
5 Standard Event Status
Bit (ESB) Summary
Message Indicates whether one or more of the enabled
Standard Events Status Register bits is set.
6 Request Service (RQS)
Message Indicates whether a SRQ (Service Request)
has occurred. Read by Serial Poll.
Master Summary Status
(MSS) Summary
Message Indicates that the instrument has at least one
reason for requesting service. Read by
*STB?.
7 Not Used. Always zero.