Allen-Bradley AADvance T9110, Руководство по безопасности, Страница: 88 / 131

88 Rockwell Automation Publication ICSTT-RM446N-EN-P - April 2018
Chapter 4 AADvance Functional Safety System Implementation
When the first I/O module is installed and the locking screw set to the lock
position, the startup and education process begins automatically. When the
locking screw is set to the unlocked position then the module will switch off
and the following indications will be displayed:
I/O Module Process Safety Time (PST)
This option allows the system integrator to configure the PST for an I/O
module, independently from the system value set through the processor
module. If no independent value is set for the module it will adopt, by default,
the top level value of PST set for the processor module. When an input module
exceeds the PST, (that is, the controller does not receive an update from the I/
O module within the PST) then the I/O module is set to a fail safe state and
returns safe values to the controller (refer to the topic - Input Modules Safety
Accuracy).
Digital/Analogue output module PST
For a digital/analogue output module the PST represents the period of a
watchdog timer that specifies the length of time the controller will allow the
module to run without receiving updates from the application. If the module
runs beyond this time without receiving any updates, it enters its shutdown
state. The default PST is 2500 ms.
Protective ability and versatility of the input module
An input module is classified as safety critical and is designed to SIL 3 level as a
single fail safe module. The input modules offer 8 or 16 isolated channels and
reports input voltage levels to the processor, for the analogue input variant the
module will convert the field current into a voltage. Input values are updated at
least once per application cycle. The same hardware is used for the 24 Vdc
digital input modules and the
4-20 mA analogue input module.
I/O modules can be replaced or installed on-line without affecting the
controller operation provided at least one is fitted and is fully operational.
However, each successive module must be installed and allowed to educate
before the installation of the next module.
Status Indicator Colors
Healthy GREEN
Ready GREEN

OFF
Run GREEN

RED
Channels 1 to 8 or 1 to 16 OFF
NOTE If the above indications are not present when the locking screw is set to the
unlocked position refer to the Troubleshooting and Repair Manual.