How do I get Measurement Results data from the VM700T back to a Remote Control program?

How do I get Measurement Results data from the VM700T back to a Remote Control program?

When the VM700T is operating under a stand-alone condition, measurements are made continuously and the measurement results data is presented to the display for the user to observe or record. In a remote control environment (RS-232 or GPIB), the measurement data is not automatically set to the controlling device when a measurement is started up and running. The remote control device/program must request a set of data from the VM700A "Turbo" or VM700T. And, to get the correct current data, a set of specific steps are necessary to place a data sample in a memory location from where the data can be retrieved.

The basic steps are...

1. Start the Measurement application
2. Store a set of results - using the getresults command
3. From the remote control program, query the VM700A "Turbo" or VM700T for the desired data.

Starting the measurement application can be accomplished in a number of ways. A common approach is to use the "execute" command. The command format is...

execute &#60character string&#62 - where the character string is the specific name of the desired measurement application. For example, "execute ColorBars" will start the ColorBars application that sits under the Measure button.

Storing a set of measurement data is accomplished most often by using the getresults command. The command format is simply...

getresults

A set of measurement data will be stored into a non-volatile memory location, in the Measurement Results directory, with a file name that is that same name as the application being executed at that time. This measurement data file is a single entity. Another "getresults" command that gets executed while using the same measurement application will overwrite the existing data file. Information that is stored by a getresults command should be off-loaded to the remote control device as soon as possible.

Note - Some measurements take a few seconds to complete their tasks and respond. The "getresults" command will respond with the name of the Measurement Results file into which the data was stored - after the command has completed its tasks. It is advisable for the programmer to write a port query that watches for the return of this information before the remote control program moves on to the next process.

Retrieving the stored data from the Measurement Results directory can be accomplished with a variety of VM700A "Turbo" or VM700T commands. The most common command, the "show" command, uses the following syntax... show &#60character string&#62 - where the character string will be the specific file within the Measurement Results directory where the data was stored.

When the "show" or other similar commands are executed, the data will be immediately available at the port for capture/download.

Note - The "getresults" command saves a set of measurement data in human readable form. The text will be aligned, appropriate headers and footers will be applied, etc. If this extra formatting data is not desired, the "res -v" command is an alternative. This command (res -v) will, upon execution, immediately send a set of "machine readable" measurement values to the active remote control port. "Res -v" data is constructed as a base number with mantissa. A separate routine in the remote control program must be built by the programmer to interpret this information correctly. Each measurement application that supports the "res -v" has a different set of items returned after a query, and the ordering of the various items is not described in the instruction manuals. This will require experimentation and note taking on the part of the programmer.