| AUTOMATION SYSTEM ARCHITECTURE
Industry standard PC hardware
and software platform
Siemens S7 PLCs
Built in redundancy for
maximum up time
Centralized PC to interrogate
any networked PLC or PC
The typical press
automation configuration has off the shelf, office PCs for
the Management System (PRIMA MS), communicating over Ethernet
to the press supervisory systems (PressNet). Each press has
its own supervisory system based on industrial PCs. Communications
between presses, and to the management system are over a plant
wide fibre optic, dual redundant, industrial Ethernet ring.
Both Ethernets run TCP/IP transport protocol. Both sets of
PCs run under Windows NT. This configuration allows the easy
flow of data at all levels. One consequence of this is that
a desk dedicated to a particular press can be switched easily
to any other press simply by re-routing database files.
The press control
systems are linked into the industrial Ethernet ring to communicate
to the higher levels. By structuring the network as an optical
ring, an efficient media redundancy can be achieved very economically,
simply by using an additional cable. In the event of failure
of an active component or on disconnection of a cable, the
network reconfigures itself as a functional line within a
few milliseconds. Expensive production failures caused by
network faults are thus avoided.
The building
blocks of the press control systems are conventional PLCs
from the Siemens S7 range. In each press area a local PROFIBUS
fieldbus highway links all the elements of the drive and control
systems. On each printing unit, I/O islands and dedicated
controllers for ink, damp and registers are linked to the
unit gateway PLC via PROFIBUS DP. Drive systems are linked
together via their own proprietary bus networks, and to the
PLC system by PROFIBUS.
Returning the
industrial Ethernet ring, it is possible to plug in a programming
PC and connect through to any of the PLCs on the system. A
central maintenance PC is usually provided for this purpose.
This architecture
allows plant variables monitored on the I/O bus of a particular
printing unit to passed up seamlessly, via the control system
PLCs, to the Press PCs and onward to the management system.
From there this data can be accessed via standard office network
interfaces from office PCs located around the customer’s
premises.
Until recently,
suppliers of press automation systems provided bespoke hardware
platforms, non-standard software packages and a variety of
serial communication protocols unique to the printing industry.
Improvements in the performance of standard, off-the-shelf
PCs and PLCs, coupled with the reduction in size of mini-controllers
and the introduction of distributed, fieldbus I/O systems
have enabled Harland Simon to move to standard platforms,
providing great customer benefits.
The following
table shows how today’s system design meets the requirements
of our customers.
| Customer Requirement |
Solution |
Benefit |
| High reliability
and low maintenance. |
Modular
system design.
Industry-standard automation
hardware from world name suppliers. |
Minimised
downtime.
Production schedules met.
Lower training costs. |
| Good diagnostics. |
Comprehensive
events and alarms system.
Operator help screens.
Central maintenance PC
with access to status information for modules throughout
the press. |
Detailed
record of events for easy faultfinding.
Historical analysis to
help plan preventative maintenance.
Minimised start up time. |
| Readily
available support. |
Worldwide
24hr technical support from Harland Simon via modem
link.
Alliance with major industrial
partners to provide global support for printing industry. |
Peace
of mind.
Readily available spares,
service and support.
Expert printing application
support from HS.
H/W & S/W support from
the local offices of our global industrial partners. |
| Flexibility,
upgradability, future-proof. Simple integration of new
systems. |
Open
system architecture
Industry standard interfaces,
i.e., Ethernet, PROFIBUS, etc.
IEC 1131-3 compliant plc
programming languages. |
Easy
access to data for monitoring and reporting.
Many suppliers of compatible
equipment.
Easily understood S/W languages. |
| On line
editing and monitoring of application programmes. |
Networked
Central Maintenance PC
On line editing of application
s/w.
Simulation facilities to
prove code before download. |
Access
from central point to all PLC controllers.
No inaccessible embedded
S/W (EPROMS). |
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