Rockwell Automation Publication ICSTT-RM446N-EN-P - April 2018
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AADvance Functional Safety System Implementation
Chapter 4
DO Termination assembly
The DO termination assembly is safety critical, it comes in two sizes —
simplex or dual. It has fuses for field output power and 8 field termination
connections for the output signals.
Analogue Output Module Safety Features
Analogue Output Module Safety Applications
The Analogue Output Module can be used in the following safety related
applications:
• The fail-safe state current of the analogue output module is less than
2mA.
• For energize to action high demand applications you must use dual
analogue output modules.
• When the module is unlocked, all of its output channels (including any
channels set to hold last state) always go to the de-energized state.
Analogue Output module Safety Functions
The Analogue output Module is rated at SIL 3 as a fail-safe simplex module.
And 1oo2D as a dual module. For high demand SIL 2 energize to action high
demand applications you must use dual analogue output modules. This
arrangement is also rated as SIL 3 for energize to action applications. Each
module provides the following safety functions:
• Commanded Values and Scaling Factor
• Fail-safe Guard Band
• Shutdown
• Module Status
• Diagnostics
Commanded Values and Scaling Factor
• User configurable value.
• The application cannot change the scaling factor; it can only be changed
by an on-line update.
Fail-Safe Guard
• User configurable value.
• Fail-safe guard is user configurable and cannot be changed by the
application; it can only be changed by an on-line update.
• The default value is 1% (0.2mA).
