Reading data from Lecroy Oscilloscope

[viet86]

    Hello, I am using a Lecroy WavePro 7300A and connect to it via LabView 8.2 using LAN connection, using the address VICP::x.x.x.x

When I tried to query for a parameter, for example MSIZ? *(the number of data points displayed in the graph) using LCRead and LCWrite (first write the query to the device using LCWrite and then using LCRead to wait for data coming from the device).

The problem is sometimes I got the string returned as "MSIZ 100", but sometimes I got only "100". This happenned the same for other command as well, i.e., sometimes the returned string is the whole command and sometimes it contains only the value of the query. Does anybody no what is the reason of this problem, please help me, I got stuck already.

Best regards,

SG.

[Dennis_Knutson]

Are you seeing this with the driver or with your own code?

[alanjb]

Hello SG,

Alan from LeCroy Tech Support here...

The format of the response depends on the setting of the communications header.  This is set with the command CHDR, and is usually issued in a driver's Initialize VI. (Or within a subvi called by Initialize.)  Which driver are you using?  Make sure to always call Intialize first.

If CHDR OFF was issued, then the response will not include the command (e.g. the response of "500"); CHDR SHORT configures a response like "MSIZ 500 SAMPLE", and CHRD LONG configures a response like "MEMORY_SIZE 500 SAMPLE"

Please note that MSIZ? does not return the number of data points displayed in the graph, but is the maximum number of points that the scope is configured to use.  For example, you can configure MSIZ 100000, but if you have the timebase set to 500ps/div, you would only get waveforms with 50 samples.

Feel free to email or call me directly for further discussion.

Best Regards,
Alan