1 - IAEA Nuclear Data Services

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5. New Developments in Instrumentation
5 • ^ • On-line Computers G. Krüger
5•1•1• Small On-line Computers Coupled with Experiments
The electronic design and development of the multiple access system
MIDAS were finished during the reporting period. After Connection of
some new nuclear physics experiments 8 facilities are in normal
operation with the system.
The total input capacity of MIDAS (Multiple Input Data Acquisition
System) amounts to 10 experiments, two of them can be located at
remote places. They are connected by fast data transmission lines.
During the year most activity concerns the development work in the
fields of programming and system organisation £1 J'. Privât libraries
for the measuring programs of the experimentors were established on
the IBM 1J11 disc, units. The archived programs in the different libraries
can be activated by experimentor's command using the command panel
at the location of the experiment.
The operation of MIDAS as an on-line-real-time multichannel
analyser with a capacity of about 262.000 channels has proven very
useful during routine operation. To accumulate multiparameter data
directly without delay a new programmed method of list-processing
were implemented.
The program package which should ensure system integrity during periods
of wrong running experiments was extended. The computer indentifies
now immediately experiment malfunctions which overload the computer.
Then the safety system closes the erroneous data way without inter­
fering the correct running measurements.
The check point program is now a standard feature of the system.
This program in connection with the new time-of-the-day real-time
clock interrupts the system in regular intervalls. The recent status
and all the intermediat-3 results of the different measurements are
saved into magnetic tape. Therefore a total breakdown of the system
cannot destroy large amount of measuring results.
The library of experiment-oriented measuring programs was considerably
extended.