SMU1._write_to_instrument(":SOUR:volt:LEV 0")
SMU1._write_to_instrument(f":SENS:VOLT:PROT {heater_max_voltage}")
SMU1._write_to_instrument(':form:elem CURR')

SMU1._write_to_instrument("TRIG:CLE") # Clear any pending input triggers
SMU1._write_to_instrument("arm:coun 100") # Perform # points in test
SMU1._write_to_instrument("arm:sour tlin") # Wait for trigger from 2400 #3
SMU1._write_to_instrument("arm:dir sour") # Skip 1st trigger event
SMU1._write_to_instrument("arm:outp none") # No output triggers from scan
SMU1._write_to_instrument("arm:ilin 3") # Define arm layer input line
SMU1._write_to_instrument("trig:coun 1") # Perform one point of test
SMU1._write_to_instrument("trig:sour tlin") # Trigger using Trigger Link
SMU1._write_to_instrument("trig:dir sour") # Skip first trigger
SMU1._write_to_instrument("trig:outp sour")  # Output trigger after source "on"
SMU1._write_to_instrument("trig:inp sour")  #?? Wait for trigger before source
SMU1._write_to_instrument("trig:ilin 1") # Input trigger line
SMU1._write_to_instrument("trig:olin 2") # Output trigger line
SMU1._write_to_instrument("trig:del 0") # Set trigger delay before source
SMU1._write_to_instrument('sour:volt:star 0.0')  # Start point for sweep
SMU1._write_to_instrument(f'sour:volt:stop {heater_max_voltage}')  # Stop point for sweep
SMU1._write_to_instrument(f'sour:volt:step {heater_max_voltage/100}')  # Define sweep step size
SMU1._write_to_instrument(f'sour:volt:rang {heater_max_voltage}')
SMU1._write_to_instrument('sour:del 0.001') # Set source delay before measure
SMU1._write_to_instrument('sour:volt:mode swe')

SMU2._write_to_instrument(":SOUR:VOLT:LEV -2")
SMU2._write_to_instrument(":SENS:CURR:PROT 10e-3")
SMU2._write_to_instrument(':form:elem CURR')

SMU2._write_to_instrument("TRIG:CLE") # Clear any pending input triggers
SMU2._write_to_instrument("arm:coun 1") # Perform only one scan
SMU2._write_to_instrument("arm:sour imm")  # Immediately start scan
SMU2._write_to_instrument("arm:dir acc")  # Wait for trigger event (IMM)
SMU2._write_to_instrument("arm:outp none")  # No output triggers from scan
SMU2._write_to_instrument("trig:coun 100") # Perform # points in test
SMU2._write_to_instrument("trig:sour tlin")  # Trigger using Trigger Link
SMU2._write_to_instrument("trig:dir acc")  # Wait for first trigger
SMU2._write_to_instrument("trig:inp sour")  # Wait for trigger before source "on"
SMU2._write_to_instrument("trig:outp none")  # Output trigger after measure
SMU2._write_to_instrument("trig:ilin 2") # Input trigger line
SMU2._write_to_instrument("trig:del 0") # Set trigger delay before source

SMU3._write_to_instrument(":SOUR:VOLT:LEV -2.5")
SMU3._write_to_instrument(":SENS:CURR:PROT 10e-3")
SMU3._write_to_instrument(':form:elem CURR')

SMU3._write_to_instrument("TRIG:CLE") # Clear any pending input triggers
SMU3._write_to_instrument("arm:coun 1") # Perform only one scan
SMU3._write_to_instrument("arm:sour imm")  # Immediately start scan
SMU3._write_to_instrument("arm:dir acc")  # Wait for trigger event (IMM)
SMU3._write_to_instrument("arm:outp none")  # No output triggers from scan
SMU3._write_to_instrument("trig:coun 100") # Perform # points in test
SMU3._write_to_instrument("trig:sour tlin")  # Trigger using Trigger Link
SMU3._write_to_instrument("trig:dir acc")  # Wait for first trigger
SMU3._write_to_instrument("trig:inp sour")  # Wait for trigger before source "on"
SMU3._write_to_instrument("trig:outp sens")  # Output trigger after measure
SMU3._write_to_instrument("trig:ilin 2") # Input trigger line
SMU3._write_to_instrument("trig:olin 1") # Output trigger line
SMU3._write_to_instrument("trig:del 0") # Set trigger delay before source

SMU4._write_to_instrument(":SOUR:VOLT:LEV -2.5")
SMU4._write_to_instrument(":SENS:CURR:PROT 10e-3")
SMU4._write_to_instrument(':form:elem CURR')

SMU4._write_to_instrument("TRIG:CLE") # Clear any pending input triggers
SMU4._write_to_instrument("arm:coun 1") # Perform only one scan
SMU4._write_to_instrument("arm:sour imm") # Immediately start scan
SMU4._write_to_instrument("arm:dir acc") # Wait for trigger event (IMM)
SMU4._write_to_instrument("arm:outp none")  # No output triggers from scan
SMU4._write_to_instrument("trig:coun 100")  # Perform # points in sweep
SMU4._write_to_instrument("trig:sour tlin")  # Trigger using Trigger Link
SMU4._write_to_instrument("trig:dir acc")  # Wait for first trigger
SMU4._write_to_instrument("trig:inp sour")  # Wait for trigger before source "on"
SMU4._write_to_instrument("trig:outp sens")  # Output trigger after measure
SMU4._write_to_instrument("trig:ilin 2")  # Input trigger line
SMU4._write_to_instrument("trig:olin 3")  # Output trigger line 
SMU4._write_to_instrument("trig:del 0.01") # Set trigger delay before source

time.sleep(0.1)

SMU3._write_to_instrument("INIT")
SMU4._write_to_instrument("INIT")
SMU2._write_to_instrument("INIT")
SMU1._write_to_instrument("INIT")

time.sleep(8)

I1 = SMU3._query_instrument("FETCh?")
I2 = SMU4._query_instrument("FETCh?")
I3 = SMU2._query_instrument("FETCH?")

SMU1._write_to_instrument("TRIG:CLE")
SMU1._write_to_instrument(':form:elem VOLT, CURR, RES')
SMU1._write_to_instrument('sour:volt:mode fix')
SMU1._write_to_instrument("TRIG:SOUR IMM") 
SMU1._write_to_instrument("TRIG:COUN 1") 

SMU3._write_to_instrument("TRIG:CLE")
SMU3._write_to_instrument(':form:elem VOLT, CURR, RES')
SMU3._write_to_instrument("TRIG:SOUR IMM") 
SMU3._write_to_instrument("TRIG:COUN 1") 

SMU2._write_to_instrument("TRIG:CLE")
SMU2._write_to_instrument(':form:elem VOLT, CURR, RES')
SMU2._write_to_instrument("TRIG:SOUR IMM") 
SMU2._write_to_instrument("TRIG:COUN 1") 

SMU4._write_to_instrument("TRIG:CLE")
SMU4._write_to_instrument(':form:elem VOLT, CURR, RES')
SMU4._write_to_instrument("TRIG:SOUR IMM") 
SMU4._write_to_instrument("TRIG:COUN 1")