User manual

Series 3700 System Switch/Multimeter Reference Manual Section 12: Status Model

3700S-901-01 Rev. C / July 2008 12-13

Status byte register

The summary messages from the status registers and queues are used to set or

clear the appropriate bits (B0, B1, B2, B3, B4, B5, and B7) of the status byte

dependent on the summary messages (0 or 1). For example, if the standard

event register is read, its register will clear. As a result, its summary message

will reset to 0, which in turn will reset the event summary bit (ESB) bit in the

status byte register.

The bits of the status byte register are described as follows:

Bit B0, measurement summary bit (MSB): Set summary bit indicates that

an enabled measurement event has occurred.

Bit B1, system summary bit (SSB): Set summary bit indicates that an

enabled system event has occurred.

Bit B2, error available (EAV): Set bit indicates that an error or status

message is present in the error queue.

Bit B3, questionable summary bit (QSB): Set summary bit indicates that

an enabled questionable event has occurred.

Bit B4, message available (MAV): Set bit indicates that a response

message is present in the output queue.

Bit B5, event summary bit (ESB): Set summary bit indicates that an

enabled standard event has occurred.

Bit B6, request service (RQS)/master summary status (MSS): Set bit

indicates that an enabled summary bit of the status byte register is set.

Depending on how it is used, Bit B6 of the status byte register is either the

request for service (RQS) bit or the master summary status (MSS) bit; when

using the GPIB serial poll sequence of the Series 3700 to obtain the status

byte (serial poll byte), B6 is the RQS bit. See Serial polling and SRQ (on

page 12-14) for details about using the serial poll sequence.

When using the *STB? common command or status.condition to read

the status byte, B6 is the MSS bit.

Bit B7, operation summary bit (OSB): Set summary bit indicates that an

enabled operation event has occurred.