System description
ADwin
2
ADwin-Gold II
, Manual February 2013
2 System description
2.1
ADwin
system concept
ADwin
systems guarantee fast and accurate operation of measurement data acquisi-
tion and automation tasks under real-time conditions. This offers an ideal basis for appli-
cations 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 milliseconds down to less than one microsecond.
System features
The
ADwin
system is equipped with analog and digital inputs and outputs, a fast pro-
cessor (32-bit floating point signal processor) and local memory. The processor is
responsible for the whole real-time processing in the system. The applications run
inde-
pendent
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 with 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
executes a program for visualizing of data, for input and operation of the processes,
togeher with access to networks and data bases, while the processor of the
ADwin
sys-
tem executes all tasks which require real-time processing concurrently.
Real-time operating system
The operating system for the DSP of the
ADwin
system has been optimized to achieve
the fastest response times possible. It manages parallel processes in a
multitasking
environment. Low priority processes are managed by time slicing. Specified high prior-
ity processes interrupt all low priority processes and are immediately and completely
executed (preemptive multitasking). High priority processes are executed as time-con-
trolled or event-controlled processes (external trigger).
Timing
The built-in
timer
is responsible for the precise scheduling of high priority processes. It
has a resolution of 3.3 nanoseconds. The
ADwin
systems are characterized by an
extremely short response time of only 100 nanoseconds during the change from a low
to a high priority process. A continously running communication process enables a con-
tinous data exchange between the
ADwin
system and the PC even while applications
are active. The communication has no influence on the real-time capability of the
ADwin
system, even so, 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 devel-
opment environment
under Windows with possibilities of online debugging. The famil-
iar, easy-to-learn BASIC instruction syntax has been extended by many more functions,
in order to allow direct access to inputs and outputs as well as by functions for process
control and communication with the PC.
