Before we investigate solutions, we will first identify and categorize the types of situations where more sophisticated communication is needed. This is accomplished by first performing a bit-wise AND of the event register and the associated enable register. The service request enable register SRER defines which bits in the status byte register set the “service request” bit. Typically, if an instrument has a condition register, the events from the condition register set the events in an associated event register. The block diagram code in Figure 7 shows how simple this can be.
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For example, to instruct an oscilloscope to perform an autosetup routine followed by a query for the waveform data, ensure that the autosetup routine is completed before retrieving the waveform data. Most Agiletn Hardware Boards: It is important to understand usage details of the message available bit for your particular instrument.
The service request enable register SRER defines which bits in the status byte register set the “service request” bit. Set the timeout of an operation to slightly longer than the longest expected wait for an instrument response. For example, if you are taking a multimeter measurement, an overload condition occurs only after an instrument takes a measurement.
All of these examples are in the Status Registers and Service Requests.
By reading only the status byte register, you can obtain a summary status of other registers. Here is a screenshot of the zgilent per your request. All of references which follow assume Windows Figure 4 shows an example of a poll to wait until the instrument completes 25 data measurements before retrieving the data.
Below is the basic procedure for handling service requests using VISA.
On an oscilloscope, you might want to be notified when a trigger event occurs. This application note describes situations and solutions that use instrument status registers with service request or polling techniques to handle zgilent where simple VISA write and read operations are not sufficient for agllent instrument control. Is the amplitude scale on the A spectrum log or linear?
I read the stuff about drivers and i installed the specific agxxx driver for the func.
Instrument Control (GPIB, Serial, VISA, IVI)
It includes a comprehensive on-line help file which complements the instrument manual. The status byte register is the main status reporting register on any IEEE Noticed that you are using serial port to communicate to instrument.
Message 9 of If your commands are not dependent on each other, no special command synchronization is necessary.
However, because the status byte register is a summary of other registers, you can use enable registers to monitor other desired instrument events. Visit a National Instruments webpage tutorial on aliasing here.
What is the use of sync, in conjunction with the o’scope? However, I found a strange thing I run this vi several times Will not appear on the error message, and do not know why? When the “service request” bit is set to True, the instrument asserts a service request.
Typically, command synchronization is used when the result of the second operation depends on the completion of the first operation. To load the dll you must include the file hpa.
Figure 5 shows how to use VISA event handling to implement query synchronization to wait until the Agilent A DMM has taken agilennt measurements and placed them in the instrument output buffer. By reading the status byte after the service request, you can determine which of the two events causes the service request.
This example also shows how the techniques shown in this application note can be used with instrument drivers.
Message 1 of As you can see the resource descriptor and instrument address fields appear empty even though I chose the proper address and instrument.
using agilent a with labview – Discussion Forums – National Instruments
A higher level of support from Hewlett-Packard for the compiled driver 3. Additional references noted at the end of this document use these other APIs. Polling the status byte, you can obtain summary information about all the instrument events. Did you modify the end characters?