ICS N4865A, Instruction Manual

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3.3 PROGRAMMING GUIDELINES
The N4865A can be used successfully to operate a LAN oscilloscope with
most test applications if a few precautions are taken. Applications that do
normal oscilloscope command or query sequences should have no problems.
Applications that depend upon oscilloscope timing may have to be adjusted
to compensate for delays in converting the commands and transmitting them
over the Ethernet.
The following multiple sequences should be avoided:
3.3.1 Multiple Triggers
Device Triggers can be sent by using the IEEE-488.1 GET command or with
the 488.2 '*TRG' Common Command. The N4865A may miss multiple GET
commands when sent to it at high speed. Multiple triggers are not found in
normal test applications as the trigger is typically followed by some GPIB
commands to read the data resulting from the trigger action. If multiple trig-
gers are required, use the 488.2 '*TRG' Common Command instead of the
488.1 GET.
3.3.2 Multiple Device Clears
Device Clear and Selected Device Clear are sent by using the IEEE-488.1 DC
or SDC commands. Normally a Device Clear is followed by a delay to allow
the oscilloscope(s) to clear their buffers and output lines. Many oscilloscopes
will not be able to input a new GPIB command for several hundred milliseconds
since they also clear their GPIB input buffer as part of the clearing process.
The N4865A may miss multiple DC or SDC commands when sent to it at high
speed. If multiple Device Clears are required, provide a minimum 100 mil-
liseconds delay between commands.
3.3.3 Multiple Serial Polls
Multiple high speed Serial Polls will return the same value. The N4865A's
GPIB Interface responds to a GPIB Serial Poll by outputting its current value
when polled. The N4865A updates its Status Byte after receiving a Service
Request and before asserting the SRQ signal and periodically thereafter at a 3
Hz rate when the N4865A is left in a talk address or not-addressed state. Se-
rial Poll updates are inhibited while the N4865A is in the listen addressed state
and resume after talking out an oscilloscope response message, after a Device
Trigger, after a Device Clear command or after an Interface Clear.