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Theory of Operation
Interfaces
To provide maximum safety within a distributed analysis system, one line
is dedicated to SHUT DOWN the system’s critical parts in case any module
detects a serious problem. To detect whether all participating modules are
switched on or properly powered, one line is defined to summarize the
POWER ON state of all connected modules. Control of analysis is
maintained by signal readiness READY for next analysis, followed by
START of run and optional STOP of run triggered on the respective lines.
In addition, PREPARE and START REQUEST may be issued. The signal
level is defined as:
• standard TTL levels (0 V is logic true, + 5 V is false),
• fan-out is 10,
• input load is 2.2 kOhm against + 5 V, and
• outputs are open collector type, inputs/outputs (wired-or technique).