Andreas K. Hüttel
and 4 contributors

NAME

Lab::Bus::VISA - National Instruments VISA bus

SYNOPSIS

This is the VISA bus class for the NI VISA library.

  my $visa = new Lab::Bus::VISA();

or implicit through instrument creation:

  my $instrument = new Lab::Instrument::HP34401A({
    BusType => 'VISA',
  }

DESCRIPTION

soon

CONSTRUCTOR

new

 my $bus = Lab::Bus::VISA({
  });

Return blessed $self, with @_ accessible through $self->config().

Options: none

Thrown Exceptions

Lab::Bus::VISA throws

  Lab::Exception::VISAError
    fields:
    'status', the raw ibsta status byte received from linux-gpib

  Lab::Exception::VISATimeout
    fields:
    'data', this is meant to contain the data that (maybe) has been read/obtained/generated despite and up to the timeout.
    ... and all the fields of Lab::Exception::GPIBError

METHODS

connection_new

  $visa->connection_new({ resource_name => "GPIB0::14::INSTR" });

Creates a new instrument handle for this bus.

The handle is usually stored in an instrument object and given to connection_read, connection_write etc. to identify and handle the calling instrument:

  $InstrumentHandle = $visa->connection_new({ resource_name => "GPIB0::14::INSTR" });
  $result = $visa->connection_read($self->InstrumentHandle(), { options });

See Lab::Instrument::Read().

connection_write

  $visa->connection_write( $InstrumentHandle, { command => $command, wait_status => $wait_status } );

Sends $command to the instrument specified by the handle, and waits $wait_status microseconds before evaluating the status.

connection_read

  $visa->connection_read( $InstrumentHandle, { command => $command, read_length => $read_length, brutal => 0/1 } );

Sends $Command to the instrument specified by the handle. Reads back a maximum of $readlength bytes. If a timeout or an error occurs, Lab::Exception::VISAError or Lab::Exception::VISATimeout are thrown, respectively. The Timeout object carries the data received up to the timeout event, accessible through $Exception->Data().

Setting Brutal to a true value will result in timeouts being ignored, and the gathered data returned without error.

connection_query

  $visa->connection_query( $InstrumentHandle, { command => $command, read_length => $read_length, wait_status => $wait_status, wait_query => $wait_query, brutal => 0/1 } );

Performs an connection_write followed by an connection_read, each given the supplied parameters. Waits $wait_query microseconds betweeen Write and Read.

CAVEATS/BUGS

Few. Not a lot to be done here.

SEE ALSO

AUTHOR/COPYRIGHT

 Copyright 2004-2006 Daniel Schröer <schroeer@cpan.org>, 
           2009-2010 Daniel Schröer, Andreas K. Hüttel (L<http://www.akhuettel.de/>) and David Kalok,
           2010      Matthias Völker <mvoelker@cpan.org>
           2011      Florian Olbrich, Andreas K. Hüttel

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.