User manual

58 Publication 1756-RM093F-EN-P - January 2010
Chapter 6 Safety Application Development
You must include a set of tests to prove the validity of the calculations
(formulas) used in your application logic. Equivalent range tests are
acceptable. These are tests within the defined value ranges, at the
limits, or in invalid value ranges. The necessary number of test cases
depends on the formulas used and must comprise critical value pairs.
Active simulation with sources (field devices) must also be included,
since it is the only way to verify that the sensors and actuators in the
system are wired correctly. Verify the operation of programmed
functions by manually manipulating sensors and actuators.
You must also include tests to verify the reaction to wiring faults and
network communication faults.
Project verification includes required functional verification tests of
fault routines, input and output channels, to ensure that the safety
system operates properly.
To perform a functional verification test on the GuardLogix controller,
you must perform a full test of the application. You must toggle each
sensor and actuator involved in every safety function. From a
controller perspective, this means toggling the I/O point going into
the controller, not necessarily the actual activators. Be sure to test all
shutdown functions, since these functions are not typically exercised
during normal operation. Also, be aware that a functional verification
test is only valid for the specific application tested. If the controller is
moved to another application, you must also perform startup and
functional verification testing on the controller in the context of its
new application.
See Functional Verification Tests
on page 14 for more information.
Confirm the Project
You must print or view the project, and manually compare the
uploaded Safety I/O and controller configurations, safety data, and
safety task program logic to make sure that the correct safety
components were downloaded, tested, and retained in the safety
application program.
If your application program contains a safety Add-On Instruction that
has been sealed with an instruction signature, you must also compare
the instruction signature, date/time, and safety instruction signature to
the values you recorded when you sealed the Add-On Instruction.
See Appendix
B, Safety Add-On Instructions for information on
creating and using safety Add-On Instructions in SIL 3 applications.