# -*- coding: utf-8 -*-
"""
Created on Tue Jan 24 15:56:51 2023

@author: Javier Navarro Montilla
"""
import pyvisa
import time
import numpy as np

#==============================================================================
# Input parameters
#==============================================================================
sweep_range = 'BEST' #Select sweep ranging: AUTO, BEST, or FIXed.
spacing = 'LIN' #Sweep type
points = 150 #Sweep number of points (max number of poits 100, otherwise buffer overrun)
start_level = -0.5e-3 #starting current value
stop_level = 0.5e-3 #ending current value
compliance = 10 #Compliance voltage (max voltage to apply on the DUT)
delay = 0.01 #Query source delay in seconds 
voltage = 1 #voltage measure range in volts
NPLC = 1 #Integration time for the 2182 in units of Number of Power Line Cycles

#==============================================================================
# Main code
#==============================================================================
rm = pyvisa.ResourceManager()
print('List of VISA resources available (check for GPIB connexion):')
print(rm.list_resources())
print('\n')
keithley = rm.open_resource('GPIB0::12::INSTR')
keithley.write('*RST')
time.sleep(2)
keithley.write(':SYST:COMM:SERIal:SEND "*rst"')
keithley.write('SYSTem:COMMunicate:SERial:BAUD 19200')
#keithley.write('SYSTem:COMMunicate:SERial:PACE XON')
time.sleep(1)
print('Arming sweep in Ketihley 6221...')
keithley.write(':SOUR:SWE:RANG ' + sweep_range)
keithley.write(':SOUR:SWE:SPAC ' + spacing)
keithley.write(':SOUR:SWE:POIN ' + str(points))
keithley.write(':SOUR:SWE:COUN 1' )
keithley.write(':SOUR:SWE:CAB ON') #Enable to abort sweep on compliance
keithley.write(':SOUR:CURR:STAR ' + str(start_level))
keithley.write(':SOUR:CURR:STOP ' + str(stop_level))
keithley.write(':SOUR:CURR:COMP ' + str(compliance))
keithley.write('SOUR:DEL ' + str(delay))
keithley.write('TRIG:SOUR TLINK') #Configure the triggert to use the cable connecting 6221 and 2182A
keithley.write('TRIG:DIR SOUR') #Control ARM source bypass
keithley.write('TRIG:OLIN 2') #Set ARM output signal line to 2
keithley.write('TRIG:ILIN 1') #Set ARM input signal line to 1
keithley.write('TRIG:OUTP DEL') #Enable/disable ARM output trigger
time.sleep(0.2)
keithley.write('TRAC:CLE')
time.sleep(0.2)
keithley.write('TRAC:POIN %i' %points) #Specify size of buffer 6221
time.sleep(0.2)
keithley.write(':SYST:COMM:SERIal:SEND ":TRAC:CLE"')
time.sleep(0.2)
keithley.write(':SYST:COMM:SERIal:SEND ":SENS:VOLT:RANG:UPP %f"'%voltage)
time.sleep(0.4)
keithley.write(':SYST:COMM:SERIal:SEND ":SENS:VOLT:NPLC %i"'%NPLC)
time.sleep(0.4)
keithley.write(':SYST:COMM:SERIal:SEND ":TRAC:CLE"') #Clear readings from buffer in 2182A
time.sleep(0.2)
keithley.write(':SYST:COMM:SERIal:SEND ":TRAC:FEED SENS"') #Select source of readings for buffer; SENSe[1],CALCulate[1], or NONE.
time.sleep(0.2)
keithley.write(':SYST:COMM:SERIal:SEND ":TRAC:POIN %i"' %points) #Specify size of buffer
time.sleep(0.2)
keithley.write(':SYST:COMM:SERIal:SEND ":TRIG:SOUR EXT"') #Select control source; IMMediate, TIMer, MANual, BUS, or EXTernal.
time.sleep(0.2)
keithley.write(':SYST:COMM:SERIal:SEND ":TRIG:COUN %i"' %points) #Specify sample count; 1 to 1024.
time.sleep(0.2)
keithley.write(':SYST:COMM:SERIal:SEND ":TRAC:FEED:CONTROL NEXT"') #Select buffer control mode (NEXT or NEVer).
time.sleep(0.5)
keithley.write(':SOUR:SWE:ARM')
time.sleep(2)
print('Waiting time: %.2f sec' %(points*delay*NPLC*10))
keithley.write(':INIT:IMM') #:INIT to take the instrument out of idle state
keithley.write(':SYST:COMM:SERIal:SEND "INIT"') #Initiate one trigger cycle.
print('Performing measurement...')
time.sleep(points*delay*NPLC*10)
keithley.write('SYST:COMM:SERIal:SEND "TRAC:DATA?"')
time.sleep(1)
empty = False
i = 0
voltage_meas = ''
while empty == False and i < 200: 
    measurement = keithley.query('SYST:COMM:SER:ENTer?')
    time.sleep(0.4)
    if len(measurement) != 1:
        measurement = str(measurement)
        print('iteration %i:' %i)
        print(measurement)
        voltage_meas = voltage_meas + measurement.strip()
    else:
        empty = True
    i = i+1

keithley.write('OUTP OFF')
print('End of the measurement')

voltage_meas = [float(j) for j in voltage_meas.split(',')]