BNMR: Histograms and Scalers

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Introduction

In the frontend, data is read from the VME scaler(s) (SIS3801 or SIS3820) and saved in histograms. The number of histograms is greater than the number of active scaler channels. For example, some scaler data are saved in separate histograms according to the helicity. In the case of Type 1 runs, the histograms are sent every cycle, whereas for Type 2 the histograms are accumulated in the frontend memory, and sent every few minutes. A data logger running on the host computer saves the data onto disk. The data is handled differently for Type 1 and Type 2 runs. For Type 1 runs, the data are saved in a MIDAS file by mlogger, and converted to MUD format by mdarc. For Type 2 runs, mdarc saved the data directly in a MUD file, and no MIDAS file is produced.

The histograms and data logging will therefore be described separately for Type 1 and Type 2 runs.

Front-end histograms and Cycle Scalers

Scaler Channels : Hardware Connections

BNMR

Table 1 : BNMR Scaler A Channels
Scaler	Module	Experiment	Channel	Contents
A	SIS3801	BNMR	1	Front scalers (16 segments summed in hardware)
A	SIS3801	BNMR	2	Front scalers (16 segments summed in hardware)
Total number of real scaler inputs : 2

Table 2 : BNMR Scaler B Channels
Scaler	Module	Experiment	Channel	Contents
B	SIS3801	BNMR	1	Scaler Internal Clock (not connected)
			2	Fluorescence Monitor (not used)
			3,4	Polarimeter counters (2)
			5,6,7,8	Neutral Beam Forwards counters (4)
			9,10,11,12	Neutral Beam Backwards counters (4)
Total number of real scaler inputs : 12

BNQR

Table 3 : BNQR Scaler B Channels
Scaler	Module	Experiment	Channel	Contents
B	SIS3820 **	BNQR	1	Scaler Internal Clock (not connected)
			17	Fluorescence Monitor (not used)
			18,19	Polarimeter counters (2)
			20	Neutral Beam Forwards counter (summed in hardware)
			21	Neutral Beam Backwards counter (summed in hardware)
			22,23,24,25	Alpha Counters
Total number of real scaler inputs : 10

NOTE: ** SIS3820 module has ECL inputs 1-16, NIM 17-32. Therefore BNQR's input channel start at 17 (NIM).

Midas histograms built in the frontend

Type 1

Only includes data from last cycle.

Table 4: Scaler A histograms (bnmr only)

Scaler A	Channel	Histogram no.	Midas Bankname
sum Back scalers	0	h0	HIBP
sum Front scalers 16-31	1	h1	HIFP
userbits	h2	UBIT
Total number of histograms: 3

6 histograms from Scaler B: Table 5 : Scaler B histograms (bnmr)

Scaler B	Channel	Histogram no.	Midas Bankname
sum scaler B (scaler clock)	1	h3	HM00
sum scaler B (fluorescence mon)	2	h4	HM01
sum scaler B (pol monitor 1)	3	h5	HM02
sum scaler B 3 (pol monitor 2)	4	h6	HM03
sum scaler B (Backwards neutral beam monitors)	5-8	h7	HM04
sum scaler B (Forwards neutral beam monitors)	9-12	h8	HM05
Total number of histograms: 6