synth.py

# -*- coding: utf-8 -*-

#    Pyblab
#    Copyright (C) 2021  Marco Pizzocaro <m.pizzocaro@inrim.it>
#
#    This file is part of Pyblab.
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#    GNU General Public License for more details.
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import pyvisa as visa


class Synth(object):
	def __init__(self, address, source, cf, pas=1, name=''):
		"""
		Synthethizer class for driving AOM frequencies.
		Optimized for Tektronix synthetizers.


		Parameters
		----------

		address: string
			visa address of the synthetizer.

		source: int
			channels source.

		cf: float
			center frequency in Hz.

		pass: int
			1 for single pass, 2 for double pass AOM.
			considered with sign.
			default = 1.


		"""
		self.address = address
		rm = visa.ResourceManager()
		self.instr = rm.open_resource(address)
		self.cf = cf	# center or original freq
		self.pas = pas
		self.name = name

		self.command = "Source{}:Freq ".format(source) + "{:.6f}"
		self.hop_command = "Source{}:FSK:Freq ".format(source) + "{:.6f}"
		
		self.write(0.)





	def write(self, shift):
		"""Write a shift from the center frequency on the synth.
		The shift is a laser ferquency shift and consider pass (single or double)
		and sign of the AOM.

		For example adouble pass AOM, plus sign, set at center freq 80 MHz,
		when asked to write 1 MHz will output 80.5 MHz.

		"""
		freq = self.cf + shift/self.pas
		cmd = self.command.format(freq)
		self.instr.write(cmd)


	def write_hop(self, shift):
		"""Write FSK Hop freq."""
		freq = self.cf + shift/self.pas
		cmd = self.hop_command.format(freq)
		self.instr.write(cmd)