Dual-channels, equivalent – Rockwell Automation 1791ES-IB16 Guard I/O EtherNet/IP Safety Modules User Manual
Page 23
Rockwell Automation Publication 1791ES-UM001D-EN-P - May 2013
23
Understand the Operation of Safety Functions
Chapter 2
The following table shows the relation between input terminal states and
controller input data and status.
Dual-channels, Equivalent
In Equivalent mode, both inputs of a pair must typically be in the same
(equivalent) state. When a transition occurs in one channel of the pair, prior to
the transition of the second channel of the pair, a discrepancy occurs. If the
second channel transitions to the appropriate state prior to the discrepancy time
elapsing, the inputs are considered equivalent. If the second transition does not
occur before the discrepancy time elapses, the channels will fault. In the fault state
the input and status for both channels are set low (off ). When configured as an
equivalent dual pair, the data bits for both channels will always be sent to the
controller as equivalent, both high or both low.
Table 2 - Terminal Input Status and Controller I/O Data
Dual-channel Mode
Input Terminal
Controller Input Data and Status
Dual- channel
Resultant
Data
Dual-channel
Resultant
Status
IN0
IN1
Safety
Input 0 Data
Safety
Input 1 Data
Safety
Input 0 Status
Safety
Input 1 Status
Dual-channels, Equivalent
OFF
OFF
OFF
OFF
ON
ON
OFF
Normal
OFF
ON
OFF
OFF
OFF
OFF
OFF
Fault
ON
OFF
OFF
OFF
OFF
OFF
OFF
Fault
ON
ON
ON
ON
ON
ON
ON
Normal
Dual-channels,
Complementary
OFF
OFF
OFF
ON
OFF
OFF
OFF
Fault
OFF
ON
OFF
ON
ON
ON
OFF Normal
ON
OFF
ON
OFF
ON
ON
ON Normal
ON
ON
OFF
ON
OFF
OFF
OFF
Fault