User Manual

Status and Events
The oscilloscope provides a status and event reporting system for the GPIB,
RS-232, and USB interfac es. This syste m informs you of certain significant
events that o
ccur within the oscilloscope.
The oscilloscope status reporting system consists of five 8-bit registers and two
queues. This section describes these registers and components, and explains how
the event handling system operates.
Registers
Overview
The registers in the event handling system fall into two functional groups:
Status Registers contain information about the status of the oscilloscope.
They include the Standard Event Status Register (SESR).
Enable Registers determine whether selected types of events
are reported to
the Status Registers and the Event Queue. They include the Device Event
Status Enable Register (DESER), the Event Status Enable Register (ESER),
and the Service Request Enable Register (SRER).
Status Registers
The Standard Event Status Register (SESR) and the Status Byte Register (SBR)
record certain types of events that may occur while the o scilloscope is in use.
IEEE Std 4 88.2-1987 defines these registers.
Each bit in a Status Register records a particular type of event, such as an execution
error or message available. When an event of a given type occurs, the oscilloscope
sets the b it that represents that type of event to a value of one. (You can disable
bits so that they ignore events and remain at zero. See Enable Registers). Reading
the status registers tells you what types of events have occurred.
The Standard Event Status Register (SESR). The SESR records eight types of
events that can occur within the oscilloscope. Use the *ESR? query to read the
SESR register. Reading the register clears the bits of the register so that the
register can accumulate information about new events.
Figure 3-1: The Standard Event Status Register (SESR)
Table 3-1: SESR bit functions
Bit Function
7(MSB) PON Power On. Shows that the oscilloscope was powered on.
On completion, the diagnostic self tests also set this bit.
TDS200, TDS1000/2000, TDS1000B/2000B, TDS2000C, TPS2000 Programmer 3-1