POL: Data format and analysis
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Introduction
This document describes the MIDAS format data banks that are output by the POL frontend fepol_32bit.exe. This frontend controls the hardware for the experiment, and programs the contents of the data banks. The analyzer reads the data from the data banks.
MIDAS Data
The data are sent out as MIDAS events which contain various banks: HISI HIS0 HIS1 HIS2 HIS3 HSUM CYCL. Some of these banks contain duplicated information (e.g. HISI vs CYCL), but they are all kept for backwards compatibility.
HISI Bank
| Word | Contents | Explanation |
|---|---|---|
| 1 | Cycle counter | Increments, counting cycles. This will count by N where N is the requested number of cycles per supercycle. |
| 2 | SuperCycle counter | Increments, counting supercycles. |
| 3 | Set Value | DAC Set Value in Volts for this event |
| 4 | Set Value Readback | Users' Readback (ADC Channel 1 Average value - see also CYCL bank ). See DAC Set value Readback **. |
| 5 | DAC Increment counter | Counts from 0 to Num Dac Increments |
| 6 | NumCycles Summed | Number of cycles summed in these histograms. Should be equal to the number of cycles per supercycle |
| 7 | Scaler buffer 1st word | DAC Set Value in Volts for this event stored in Scaler data buffer as the first word for checking. Should always be equal to word 3 (but may have rounding errors due to conversion to integer mV and back). |
Notes:
- Cycle counter contains the user-requested number of cycles, so if parameter Discard first cycle is set, the first cycle will already have been discarded. Compare with #CYCL bank, where the actual number of cycles is recorded.
- ** The DAC is used to drive a high voltage power supply. The Set Value Readback is read from ADC Channel 1, which is connected by the users to their own voltage readback. The actual readback of the DAC itself is found in #CYCL bank, read from ADC Channel 0.
HIS0,HIS1,HIS2,HIS3 Banks
The banks HIS0...HIS3 are the histogram banks for Scaler Input channels 0-3. These contain the cumulative sums of each time bin summed over the number of cycles/supercycle at a particular DAC increment value. Summing all the bins together for each channel should give the same value as in the HSUM bank. The histograms are cleared after each supercycle.
| Word | Contents |
|---|---|
| 1 | Time bin 0 summed for one SuperCycle |
| 2 | Time bin 1 summed for one SuperCycle |
| ... | ............ |
| ... | ............ |
| N | Last time bin summed for one SuperCycle |
HSUM Bank
The HSUM bank contains the sums of all the time-bins (output as histograms in Event 5) for each Scaler Channel. The sums are cleared after each SuperCycle.
| Word | Contents |
|---|---|
| 1 | Sum of all the time bins of Scaler input 0 for one SuperCycle |
| 2 | Sum of all the time bins of Scaler input 1 for one SuperCycle |
| 3 | Sum of all the time bins of Scaler input 2 for one SuperCycle |
| 4 | Sum of all the time bins of Scaler input 3 for one SuperCycle |
CYCL Bank
| Word | Contents | Explanation |
|---|---|---|
| 1 | Scan type code | Always 1 - indicates a DAC scan |
| 2 | Cycle counter | Increments, counting cycles. Cycle Counter will count by N |
| 3 | SuperCycle counter | Increments, counting supercycles. If there are N cycles in a supercycle, the Cycle Counter will count N times as fast as the Supercycle Counter. |
| 4 | Cycles/SC counter | Counts cycles within each supercycle. If there are N cycles per supercycle, this counter should always show N. |
| 5 | Sweep counter | Increments, counting the number of complete DAC sweeps (or scans). |
| 6 | Skipped-cycle counter | Counts number of cycles skipped. If first cycle is discarded each SC, this number will be same as SuperCycle Counter. |
| 7 | Num cycles histogrammed | Should be the same as Cycle counter. |
| 8 | DAC Increment counter | Counts DAC increments within a sweep. If the number of DAC increments selected per sweep is M, counter will vary from 0 to M. |
| 9 | DAC Set Value | DAC Set value in Volts (DAC Output 0) |
| 10 | ADC0 | Galil ADC0 Input (connected to DAC Output 0 ) i.e. DAC Readback in Volts |
| 11 | ADC1 | Galil ADC1 Input (Volts) |
| 12 | ADC2 | Galil ADC2 Input (Volts) |
| 13 | ADC3 | Galil ADC3 Input (Volts) |
| 14 | ADC0 Average | Average value of ADC Input 0 (DAC Readback in Volts) |
| 15 | ADC1 Average | Average value of ADC Input 1 (Volts) |
| 16 | ADC2 Average | Average value of ADC Input 2 (Volts) |
| 17 | ADC3 Average | Average value of ADC Input 3(Volts) |
- NOTES
ADC Channel 1 (user-defined DAC readback) is also output in the #HISI Bank. Since the HISI bank is assembled at a slightly different time to the CYCL bank, the values in the two banks may differ because of jitter on the ADC readback. The average values are generated to average out this jitter.
Example of EventID 5
In this example, only Scaler Input 1 has been connected to a clock, so only the HIS1 bank has counts.
------------------------ Event# 7 ------------------------ Evid:0005- Mask:0020- Serial:1- Time:0x5339eea8- Dsize:352/0x160 #banks:8 - Bank list:-CYCLHISIHIS0HIS1HIS2HIS3HSUM- Bank:CYCL Length: 68(I*1)/17(I*4)/17(Type) Type:Real*4 (FMT machine dependent) 1-> 1.000e+00 1.000e+03 5.000e+00 2.000e+02 1.000e+00 5.000e+00 1.000e+03 4.000e+00 9-> 4.000e-02 4.150e-02 3.943e-01 9.000e-04 9.263e+00 4.150e-02 3.913e-01 0.000e+00 17-> 9.263e+00 Bank:HISI Length: 28(I*1)/7(I*4)/7(Type) Type:Real*4 (FMT machine dependent) 1-> 1.000e+03 5.000e+00 4.000e-02 3.958e-01 4.000e+00 1.000e+00 4.000e-02 Bank:HIS0 Length: 400(I*1)/100(I*4)/100(Type) Type:Unsigned Integer*4 1-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 9-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 17-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 25-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 33-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 41-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 49-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 57-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 65-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 73-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 81-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 89-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 97-> 0x00000000 0x00000000 0x00000000 0x00000000 Bank:HIS1 Length: 400(I*1)/100(I*4)/100(Type) Type:Unsigned Integer*4 1-> 0x000003e8 0x000003e8 0x000003e8 0x000003e8 0x000003e8 0x000003e8 0x000003e8 0x000003e8 9-> 0x000003e8 0x000003e8 0x000003e8 0x000003e8 0x000003e8 0x000003e8 0x000003e8 0x000003e8 17-> 0x000003e8 0x000003e8 0x000003e8 0x000003e8 0x000003e8 0x000003e8 0x000003e8 0x000003e8 25-> 0x000003e8 0x000003e8 0x000003e8 0x000003e8 0x000003e8 0x000003e8 0x000003e8 0x000003e8 33-> 0x000003e7 0x000003e9 0x000003e7 0x000003e8 0x000003e8 0x000003e8 0x000003e8 0x000003e8 41-> 0x000003e8 0x000003e9 0x000003e7 0x000003e8 0x000003e9 0x000003e8 0x000003e7 0x000003e9 49-> 0x000003e8 0x000003e8 0x000003e7 0x000003e9 0x000003e8 0x000003e8 0x000003e8 0x000003e8 57-> 0x000003e8 0x000003e8 0x000003e9 0x000003e7 0x000003e9 0x000003e8 0x000003e8 0x000003e7 65-> 0x000003e9 0x000003e8 0x000003e8 0x000003e8 0x000003e8 0x000003e8 0x000003e8 0x000003e7 73-> 0x000003e8 0x000003e8 0x000003e9 0x000003e8 0x000003e7 0x000003e9 0x000003e7 0x000003e8 81-> 0x000003e8 0x000003e8 0x000003e8 0x000003e8 0x000003e8 0x000003e8 0x000003e8 0x000003e7 89-> 0x000003e8 0x000003e8 0x000003e8 0x000003e8 0x000003e8 0x000003e8 0x000003e8 0x000003e8 97-> 0x000003e8 0x000003e8 0x000003e8 0x000003e8 Bank:HIS2 Length: 400(I*1)/100(I*4)/100(Type) Type:Unsigned Integer*4 1-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 9-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 17-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 25-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 33-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 41-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 49-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 57-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 65-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 73-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 81-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 89-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 97-> 0x00000000 0x00000000 0x00000000 0x00000000 Bank:HIS3 Length: 400(I*1)/100(I*4)/100(Type) Type:Unsigned Integer*4 1-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 9-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 17-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 25-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 33-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 41-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 49-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 57-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 65-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 73-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 81-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 89-> 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 97-> 0x00000000 0x00000000 0x00000000 0x00000000 Bank:HSUM Length: 32(I*1)/8(I*4)/4(Type) Type:double*8 1-> 0.00000e+00 9.99990e+04 0.00000e+00 0.00000e+00