Beginners’ manual Series xx7│Document 26/835; Version E 2│22.04.2005
Saia-Burgess Controls AG
User community and user benefi ts
Introduction
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1 Introduction
1.1 User community and user benefits
Manufacturers who see control technology as an opportunity to differentiate
themselves and sharpen their profile, and who also wish to take advantage of the
wide user acceptance the resource pool available for Step®7, are best served by the
Saia® PCD Series xx7 control system, as they can gain the most benefit from the
high level of service and performance of the Saia PCD and the flexibility and SPS
expertise that we can offer.
On the other hand, system integrators with no experience of Saia PCDs, who wish to
use the high level of service and performance of the Saia PCDs in one-off production
plant projects to replace a high-performance Siemens control system (S7-400)
for cost reasons, will gain little real benefit from our Saia® PCD Series xx7. This is
especially true where many other intelligent Siemens devices are installed, with
interfaces that are not based on open standards alone.
We put great effort into systematic testing to ensure compatibility with the Step®7/
Higraph/SCL tools and the like. However, we cannot and do not wish to copy and test
the characteristics and behavior of a high-performance Siemens SPS deployed as a
control for Siemens “Total Integrated Automation”.
1.2 Differences from other Step®7-programmable controls
Saia-Burgess has implemented all the CPU operating system functionality as
firmware components. We do not use any “miracle chips”. We are therefore
dependent on nobody, but our customers gain the advantage of rapid change/
enhancement to the operating system.
1.2.1 Portability and compatibility
The Saia® PCD Series xx7 operating system interprets the Step®7 AWL code. This
means that the Step®7 program can be executed in any AWL-based language such
as KOP, FUP, Higraph, SCL or S7-Graph. Calls to Siemens-specific system functions
(e.g. for special modules such as communication processors), or access to additional
peripherals, may require modifications to the program.
For more details on this and on the system functions themselves, refer to the
Technical Information document TI 26/353 (xx7 operating system).
There is not complete compatibility. However, the Saia® PCD Series xx7 controls
are Step®7 programmable. The main restrictions arise where specific local Simatic
modules, communication processors or functional modules are an absolute
requirement. Because of differences in hardware structure, these cannot be
integrated into the xx7 system. Saia-Burgess offers cost-effective alternative solutions
that involve little engineering effort to implement. The instruction sets and component
addresses for the xx7 controls roughly correspond to those of the Siemens
CPU412/414. It is important to check that any Siemens system functions used are
also available in the Series xx7 operating system. For more information, refer to the
Technical Information document TI 26/353 (xx7 operating system). More detailed
information on programming system functions can be found in manual “26/797 xx7
System functions”.
