GPIB Manager class

Matlab class to check a gpib interface for all connected devices and read voltages from connected keithley multimeters and lockin amplifiers. This scripts was written primarily to check the availability of Keithley 2000 (2010) multimeters and Stanford Research Systems (SRS) lockin amplifiers, but can easily be expanded to control more laboratory equipment. The class provides a level of usability by checking user input for compatibility with the equipment and returning informative warnings and error messages. The class is a singleton, preventing the user from accidentally instantiating multiple objects that control the same gpib interface. Currently, GPIBManager only checks for gpib instruments on secondary address '0'. To check at another secondary address, modify the FindAll function by changing the secondary address in the 'address' string.
N.B.: Every time new equipment is (dis)connected, the UpdateConnections function should be run.

Functions:
getInstance - instantiate the GPIBManager object
FindAll - check and store connected equipment on a gpib interface.
InitKeithley - initialize keithley settings.
InitLockin - initialize lockin settings.
Open - open a visa-gpib connection with instruments.
CloseAll - close all gpib connections to all connected instruments.
ReadKeitleys - return a vector with the value of all connected keithleys.
ReadLockins - Return two vectors with the x/r and y/theta values of all connected lockins.
GetKeithleyNums - return a list with the gpib numbers of all connected keithleys.
GetLockinNums - return a list with the gpib numbers of all connected lockins.
GetEquipmentList - Return a list with equipment names.
UpdateConnections - Recheck all gpib ports and store connected instruments

A detailed description of all the class' functionality is provided by GPIBManager_matlab_class.pdf