FAST ComTec MCA4A, User Manual

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Software Description
4.1.10 System Definition
The “System...” item in the settings menu opens the System Definition dialog box. S everal MCA's can be
combined to form up to 4 separate systems that can be started, stopped and erased together. The use of the
Digital Input / Output and the GO-Line can be defined: It can be used either to show the ON or OFF status of
the systems if the checkbox Status Dig 0..3 is marked. At the respective pins +5 Volt are output if an
acquisition is running and 0 V if not. Alternatively, it can be used for example with a sample changer by
checking "Value inc. at Stop". Here, the 8-bit value entered in the edit field (a number between 0 and 255) is
output at the Dig I/O port. This value will always be incremented by 1 if the MCA4 is stopped. The Invert
checkbox allows inverting the logical level. See also the commands pulse and waitpin how to handshake a
sample changer or synchronize sequential cycles with a target mover, see the control language in 4.3. The
Radio buttons Push-Pull and Open Drain define the output mode of the Dig I/O ports.
It is also possible to use the digital input 4 as an external trigger for starting the system (DESY control line). If
the corresponding checkbox Start with Dig 4 is marked, a start command for the respective system will not
immediately start the system. After the start command, the digital input will be permanently checked for its
logical level. If the level changes from high to low, the data for the system is cleared and it will then be
started. It will stop if the level returns to high (or vice versa if Invert is marked) and can again be restarted
with the next level change. A stop command for the system will finish the digital input checking. By checking
Clear before Start the spectra is cleared before the start. As an alternative to controlling Start/stop via digital
input 4 also the GO-line can be used by checking Start with GO. This is better as the GO-line controls the
hardware directly.
The Use of the GO-Line is controlled via the 3 checkboxes Watch, High when ON, and Low at Stop. The GO
line gates directly the hardware. "Low at Stop" means that the GO line is immediately pulled down by the
hardware when a sweep preset is reached, or as fast as possible by the software at any other stop. If Tag
bits are used, the digital I/O port is used as an input for the tag bits exclusively, see chapter 4.1.7.
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Fig. 4.18: System Definition dialog box