#!dimctrl --exec # dimctrl script > > ------------------------------------------- > Bias and Feedback StartUp (Current Calibration) > ------------------------------------------- .w 2000 # As a First step we want to calibrate the current, which are read from the bias crate, # and not take a DRS calibration, as it is mentioned in the data taking page... # so for this we should get the feedback and biasctrl programs into known states # I think it is good to try a RECONNECT to the bias, and make sure the voltage is off # # NOTE: # The ideas in the line above are both valid, but both not done. # This is *not good* # Since we do not know, what the feedback program is doing at the moment, we should as well, # tell it to keep its mouth shut ... just to be sure, we know whats going on > stopping feedback FEEDBACK/STOP .w 2000 # stopping should always be possible, and end in state 'Connected'(6) .s FEEDBACK 6 > ..done #BIAS_CONTROL/RECONNECT # If we were disconnected, and this was the first try of the night, the bias_ctrl should # be in state 'VoltageOff'(7) more or less immediately #.s BIAS_CONTROL 3 #.s BIAS_CONTROL 7 5000 # if these assumptions are all wrong, then we might have been properly connected anyway, # and just have to ramp down... lets do it, but wait forever, in case it does not work > switching off bias BIAS_CONTROL/SET_ZERO_VOLTAGE .w 2000 .s BIAS_CONTROL 7 > ...done # in case we reach this line, the voltages are all off, and the feedback does not do anything # So lets do the current calibration, therefor we tell the bias crate to ramp up just 1 single DAC count(~22mV) # the result of this action is, to get bias_ctrl into the state 'VoltageOn'(9), but since we only go one DAC count it shouldn't take long > setting bias globally to 1 DAC BIAS_CONTROL/SET_GLOBAL_DAC 1 .w 2000 .s BIAS_CONTROL 9 > ...done # now we may tell the feedback program to calibrate the currents ... # I do not understand, if I have to explicitely allow the feedback program to generate output, # or if it just produces output... # As far as I understand, the feedback output enable status is the same, # as it was before I send the STOP command... so it is unknown at this point. # and in addition enabling or disabling the output, when STOPed is not possible as far as I know... # I try to enable it anyway. > enabling output for feedback FEEDBACK/ENABLE_OUTPUT yes .w 2000 > ...done > calibrating bias crate current readings... FEEDBACK/CALIBRATE_CURRENTS .w 5000 # in order to find out when the calibration ends, we have to wait for the transistion from state # 'Calibrating'(13) back to 'Connected'(6) .s FEEDBACK 13 .s FEEDBACK 6 # Thomas Bretz told me, that the feedback, after this step has disabled its output # and is in the mode, we might call 'temperature control' even there is no temerature beeing controlled. # I don't know where the voltage is ... in order to perform the calibration, the feedback had to # ramp up to 2V below the operational voltage, i.e. about 1V below the breakdown voltage # We want to take a DRS amplitude calibration so we have to ramp down the bias voltage. # this 10sec wait is needed in order for the bias not to disconect all the time... > ... current calibration done .w 10000 > switching off bias BIAS_CONTROL/SET_ZERO_VOLTAGE .w 5000 .s BIAS_CONTROL 7 > ...done # now we want to take a run, with dark counts events # so we need to ramp up the voltage # we want to use the 'current control' more so we give the commands for this... > switching on current controll feedback ... FEEDBACK/STOP FEEDBACK/START_CURRENT_CONTROL 0.0 FEEDBACK/ENABLE_OUTPUT yes # the feedback should be in state 'CurrentControl'(12) now .s FEEDBACK 12 > ... done > switching on bias # now we give the feedback a hint, that it may ramp ... BIAS_CONTROL/SET_GLOBAL_DAC 1 # after this command the bias_ctrl should be in state 'VoltageOn'(9) after a second or so .s BIAS_CONTROL 9 > ...1 DAC globally set # then usually it takes some time until the feedback has enough information to really start controlling the voltage # when the feedback actually kicks in, the bias is first in state 'Ramping'(5) for some seconds and finally in 'VoltageOn'(9) # again .s BIAS_CONTROL 5 > ...ramping to nominal voltage .s BIAS_CONTROL 9 > ...bias on # here we should wait 45 sec in order for the current control to get enough current readings and temp readings to stabilize.. > waiting 45sec for the current control to stabilize... .w 45000 > ... done # at the end the bias voltage should be ramped down, since in a few seconds a shifter wit ha flashlight # will come out to open the shutter... > switching OFF bias ... BIAS_CONTROL/SET_ZERO_VOLTAGE .s BIAS_CONTROL 7 > ...done > ---------------------------------------------------- > Bias and Feedback StartUp (Current Calibration) > ... done. > ---------------------------------------------------- >