System description
ADwin
2
ADwin-Gold
USB / ENET, manual version 3.8, October 2005
2 System description
2.1
ADwin
system concept
ADwin
systems guarantee fast and accurate operation of measurement data
acquisition and automation tasks under real-time conditions. This offers an
ideal basis for applications such as:
– very fast digital closed-loop control systems
– very fast open-loop control systems
– data acquisition with very fast online analysis of the measurement data
– monitoring of complex trigger conditions and many more
ADwin
systems are optimized for processes which need
very short process
cycle times
of one millisecond upto some microseconds.
System features
The
ADwin
system is equipped with analog and digital inputs and outputs, a
fast processor (32-bit floating point signal processor) and local memory. The
processor is responsible for the whole real-time processing in the system. The
applications are running
independent
of the PC and its workload.
Processor
The processor of the
ADwin
system processes
each
measurement value at
once
.
In one cycle you can acquire the status of the inputs, process the status by the-
help of any mathematical functions, and react to the results, even at very fast
process cycle times of some microseconds. This results in a perfect and logical
work sharing: The PC runs a program for visualizing of data, for input and oper-
ation of the processes, togeher with access to networks and data bases, while
the processor of the
ADwin
system executes all tasks which require real-time
in parallel.
Real-time operating
system
The operating system for the DSP of the
ADwin
system has been optimized
to reach the fastest response times possible. It manages parallel processes in
a
multitasking
manner. Low priority processes are managed by time slicing.
Requested high priority processes interrupt all low priority processes and are
instantaneously and completely executed (preemtive multitasking). High prior-
ity processes are executed as time-controlled or event-controlled processes
(external trigger).
Timing
The built-in
timer
is responsible for the precise calling of high priority pro-
cesses. It has a resolution of 25 nanoseconds. The
ADwin
systems are char-
acterized by an extremely short response time of only 300 nanoseconds during
the change from a low to a high priority process. A continously running com-
munication process enables a continous data exchange between the
ADwin
system and the PC even during applications in process. The communication
has no influence on the real-time capability of the
ADwin
system, neverthe-
less, it is possible to exchange data at any time.
ADbasic
The real-time development tool
ADbasic
gives the opportunity to create time-
critical programs for
ADwin
systems very easily and quickly.
ADbasic
is an
integrated development environment
under Windows with possibilities for
online debugging. The habitual, easy-to-learn BASIC instruction syntax has
been extended by many more functions, in order to get direct access to inputs
and outputs as well as by functions for process control and communication with
the PC.
