ref_port

bapsflib.lapd.constants.constants.ref_port = <<class 'bapsflib.lapd.constants.constants.BaPSFConstant'> name='LaPD reference port number' value=53 uncertainty=0 unit='' reference='Basic Plasma Science Facility'>

BaPSF Constant: LaPD \(z = 0\) reference port (most Northern port and \(+z\) points South towards south cathode)