User Manual

Status and Events
Synchronizat
ion M ethods
Overview
Although most commands are completed almost immediately after being received
by the oscilloscope, some commands start a process that requires time. For
example, onc
e a single sequence acquisition command is executed, depending
upon the applied signals and trigger settings, it may take an extended period
of time b efore the acquisition is complete. Rather than remain idle while the
operation is in process, the oscilloscope will continue processing other commands.
This means that some operations will no t be completed in the order that they
were sent.
Sometimes the result of an operation depends on the result of a n earlier operation.
A first operation must complete before the next one is processed. The oscilloscope
status a
nd event reporting system is designed to a ccommodate this process.
The Operation Complete (OPC) bit of the Standard Event Status Register (SESR)
can be p
rogrammed to indicate when certain oscilloscope operations have
completed and, by s etting the Event Status Enable Register (ESER) to report
OPC in the Event Status Bit (ESB) of the Status Byte Register (SBR) and setting
the Service Request Enable Register (SRER) to generate service request upon a
positive transition of the ESB, a service request (SRQ) interrupt can be generated
when certain operations comple te as described in this section.
The following oscilloscope operations can generate an OPC:
Table 3-3: Oscilloscope operations that can generate OPC
Command Conditions
ACQuire:STATE ON or ACQuire:STATE RUN Only when ACQuire:STOPAfter is
set to SEQuence
*CAL?
CALibrate:CONTINUE
CALibrate:FACtory
CALIbrate:INTERNAL
FACtory
HARDCopy STARt
RECAll:SETUp <file as quoted string>
RECAll:WAVEform <file as quoted string>
*RST
SAVe:IMAGe <file as quoted string>
SAVe:SETUp <file as quoted string>
SAVe:WAVEform <file as quoted string>
For example, a typical application might involve acquiring a single-sequence
waveform and then taking a measurement on the acquired waveform. You could
use the following command sequence to d o this:
TDS200, TDS1000/2000, TDS1000B/2000B, TDS2000C, TPS2000 Programmer 3-7