Using mock instruments for testing.

Connection logging.

You can monitor all method calls to the interface defined in Connection.pm. To do this, you use a Log connection:

 my $instr = Instrument('Agilent34410A', {
           connection_type => 'LinuxGPIB::Log',
           logfile => 'mylogfile.yml'
           gpib_address => 17});

This will log all calls to the connection's methods:

Clear

Write

Read

Query

BrutalRead

LongQuery

BrutalQuery

timeout

block_connection

unblock_connection

is_blocked

This information is then stored in mylogfile.yml. The contents of this file might look like this:

 ---
 id: 0
 method: is_blocked
 retval: 0
 ---
 command: FUNCTION 'volt:ac'
 id: 1
 method: Write
 retval: 1
 ---
 id: 2
 method: is_blocked
 retval: 0
 ---
 command: FUNCTION?
 id: 3
 method: Query
 retval: '"VOLT:AC"'
 ---
 command: '*RST'
 id: 4
 method: Write
 retval: 1

For each call, we log the method name and the return value. Some methods receive additional parameters, like the command sent to the instrument.

Mock instruments.

Mock instruments are the main ingredient when building unit tests for the Lab::Measurement package.

Using the output from a Log connection, it is possible to rerun a measurement script without using the physical instrument.

This is done by providing a previously recorded log file to the Mock connection:

 my $instr = Instrument('Agilent34410A', {
           connection_type => 'Mock',
           logfile => 'mylogfile.yml'});

The Mock connection will croak, if the calls to it deviate from the provided log file.