On-Line Data-Acquisition Systems in Nuclear Physics, 1969

by National Research Council . Ad Hoc Panel on On-line Computers in Nuclear Research

The computer-independent bus system has not been expensive in manpower. It has required about 9 man-months in design and debugging and somewhat less time in construction. The registers cost about $300, as mentioned, and the controllers $1500 to $2000 depending on the need for cable drivers.

7. Costs

The costs of the RB multiple-computer system are given in Table 6. The figures are approximate and not the result of detailed accounting.

TABLE 6  Systems Costs of Rutgers-Bell Multiple-Computer System
a.	Original 910/925 system
	Systems/programming		1 man-year
	Interface design	910	6 man-months
		925	3 man-months
	Interface construction	910	$15,000 including display
		925	$11,000
	Computer costs	910	$3,500/month; bought with rental allowance for $58,000
		925	$ 4,800/month; including line printer and card reader
	Maintenance and updating	910	1 man-year, over 6 years
b.	New system (including some components not yet acquired)
	Planning and expediting		1½ man-years
	Systems programming		3 man-years to date, 2 more expected
	ADC interface
	Engineering design		$20,000
	Construction and test		9,000 spent outside
	Parts		11,000
	Time spent locally		9 man-months
	Data bus system
	Parts		$ 5,000
	Design and debug		9 man-months
	Construction		6 man-months
	Display disk system
	Disk with 64 heads and amplifiers		$ 24,000
	Interface to Sigma 5, Sigma 2, and displays		$ 10,000 (estimated, since design is not complete)
	4 14-in. displays with analog rotators and light pens		$ 12,000
	Three teletypes		$ 5,000
	Miscellaneous technical work		1 man-year
	Computer costs
	Sigma 2		$ 50,000
	Sigma 5		$440,000 purchase equivalent, but part is leased
	TOTALS FOR NEW SYSTEM
	CASH COSTS		$586,000
	TIME		8 man-years professional
			3 man-years technician

G. A PROCESS-CONTROL SYSTEM: THE BROOKHAVEN MULTIPLE SPECTROMETER CONTROL SYSTEM (MSCS)

1. Introduction

In 1965, a system based on an SDS 920 computer was put into operation at the Brookhaven National Laboratory to control data-acquisition processes involving eight neutron spectrometers and one x-ray spectrometer. The neutron spectrometers are located on the floor surrounding the High Flux Beam Reactor (HFBR); the x-ray spectrometer was placed in the same building in order to facilitate linking it to the computer. The system can control the execution of experiments on all nine sets of apparatus simultaneously, yet each experimenter feels that he is working essentially independently of all other users. The system controls all angular rotations of crystals and counters, all detector counting, the data displays, the input and output operations, and automatic error responses.

It can also perform most of the calculations necessary for real-time guidance of the course of the experiments. For example, the experimenter can mount a crystal on a goniometer at approximately the correct angular orientation, then he can specify to the computer where several peaks should be found, whereupon the computer will direct the execution of a trial experiment to find where the peaks do, in fact, occur, executing least-squares calculations in the process, after which the error in crystal orientation is known and the angular scales are automatically corrected. In another example, the computer is given as input information the crystal constants (unit cell) and the zone orientation of the crystal on the goniometer and is asked to produce a scanning of a given part of reciprocal space. The computer then calculates where to look, turns to a correct angle to check the intensity of a central peak, and performs the other necessary steps, making many decisions as it controls the execution of the entire experiment.

2. Description of System