Check status of VISA resource
Create a connection to an oscilloscope using the VISA-GPIB interface.
v = visadev("GPIB0::11::INSTR");
Configure the oscilloscope to request service when a command error occurs.
writeline(v,"*CLS"); writeline(v,"*PSC 0"); writeline(v,"*ESE 0"); writeline(v,"DESE 0"); writeline(v,"*SRE 32");
"Volt?" query to the oscilloscope. Since it is an
invalid command, a command error occurs.
Check whether the oscilloscope has requested service.
ans = logical 1
Since a command error occurs when you send the
the oscilloscope has requested service.
tf— True or false result
True or false result, returned as a
status— Status byte register
Status byte register, returned as a positive integer from 0 to 255. You can convert
this value to its binary value using
dec2bin and interpret each bit
as information about the VISA resource.
Each bit is associated with a type of event. For example, bit 6 (RQS) indicates the status of the VISA resource service request.
Status Byte Register Bits
Instrument-specific summary messages.
The Message Available bit indicates if data is available in the Output Queue. MAV is 1 if the Output Queue contains data. MAV is 0 if the Output Queue is empty.
The Event Status bit indicates if one or more enabled events have occurred. ESB is 1 if an enabled event occurs. ESB is 0 if no enabled events occur. You enable events with the Standard Event Status Enable Register.
The Master Summary Status summarizes the ESB and MAV bits. MSS is 1
if either MAV or ESB is 1. MSS is 0 if both MAV and ESB are 0. This bit is
obtained from the
The Request Service bit indicates that the instrument requests service. This bit can be used for serial polling.
Instrument-specific summary message.