Rockwell Automation 1753-DNSI DeviceNet Safety Scanner for GuardPLC Controllers - Manual (Page 11)

1 Publication 1753-UM002A-EN-P - July 2005
Chapter
1
Before You Begin
This chapter provides an overview of communication between the
1753-DNSI and the GuardPLC controller. Before configuring your
1753-DNSI module, you must understand:
• the safety concept of the system
• the data exchange between the GuardPLC controller and
DeviceNet devices through the 1753-DNSI module
• the roles of RSNetWorx for DeviceNet and RSLogix Guard PLUS!
software in the safety system
• the features of the DeviceNet Safety Scanner
• the physical layout of your network
Safety Concept The DeviceNet Safety Scanner for GuardPLC Controllers is certified for
use in GuardPLC safety applications up to and including Safety
Integrity Level (SIL) 3, according to IEC 61508, and Category (CAT) 4,
according to EN 954-1, in which the de-energized state is the safety
state.
The DeviceNet Safety Scanner and the GuardPLC system use the
following mechanisms to support the integrity of the data they
exchange:
• Safety Network Number – A unique number that identifies the
Safety Network. Each DeviceNet sub-network that contains
safety nodes must have one unique Safety Network Number.
• Configuration Signature – The combination of an ID number,
date, and time that uniquely identifies a specific configuration
for a safety device.
IMPORTANT
For SIL 3 and CAT 4 safety system requirements,
including proof test intervals, system reaction time,
and PFD/PFH calculations, refer to the GuardPLC
Controller Systems Safety Reference Manual,
publication number 1753-RM002. You must read,
understand, and fulfill these requirements prior to
operating a GuardPLC controller-based SIL 3 or CAT
4 safety system.