Allen-Bradley 1756 Series, User Manual, Page: 50 / 136

50 Rockwell Automation Publication 1756-UM013B-EN-P - October 2019
Chapter 3 1756-IB16S Input Module Features
Safety Input Fault Reset
The I/O channel supports a module-level user-configurable 'Latch Fault until
reset via output tag' mode and recovers from these faults:
• Field Power Off Detection
• Safety Input Short Circuit
'Latch Fault until reset via output tag' mode is Enabled
When Latch Fault... mode is Enabled, the I/O channel holds safety input fault
indications until it checks that the fault is removed. If the fault is removed, the
channel clears the fault status only upon detecting that the ResetFault in its
consume assembly channel sees a rising edge.
'Latch Fault until reset via output tag' mode is Disabled
When Latch Fault... mode is Disabled (default), the I/O channel holds safety
input fault indications for 1 second until it checks if the fault is removed. If the
fault is removed, the channel clears the fault status only upon detecting the safety
input is low on the screw. If not, the channel continues to check if the fault is
removed.
Safety Input Delay Time
You can increase the time that it takes for an input point to transition from On to
Off and Off to On on the 1756-IB16S module. The increase in time is a delay of
the signal from the module to the controller.
The RPI defines a rate at which the owner-controller and the module exchange
data (2…500 ms). For example, if you set the RPI at 10 ms and use an input delay
time of 2 ms, it could take up to12 ms for a signal change to be seen at the
controller.
An increase in the time it takes to transition from one state to another improves
noise immunity within a signal.
To set the Input Delay Time on the 1756-IB16S module, see Edit the 1756-
IB16S Module Configuration Categories on page 88 .