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Rockwell Automation Publication 35-UM001A-EN-P - May 2022
Chapter 6 Safety Functions
Determining Safety Input Alarm Type
To determine if a safety input is reporting an alarm, examine the safety input’s
input status attribute (see
Safety Input Status on page 127
for information on
accessing this attribute). If the input is reporting an alarm, the alarm type can
be accessed through CIP messaging.
The safety input alarm type can be read via CIP messaging. See
for the
attributes that are required to read the alarm type.
Safety Input Alarm Recovery
If an error is detected, the safety input data remains in the off state. Follow this
procedure to activate the safety input data.
1. Remove the cause of the error.
2. Place the safety input (or safety inputs if in dual channel mode) into the
safe state.
The safety input status turns on (alarm cleared) after the input-error
latch time has elapsed.
Safety Output Operation
The safety outputs can operate only in dual channel bipolar mode. The safety
output can also be configured to run pulse test diagnostics.
The safety output assembly controls the bipolar output only when the drive is
not using the SBC function. If the SBC function is used, it controls the output.
Table 47 - MSG Configuration for Safety Input Alarm Type
Parameter
Value
Description
Service Code
0x0E
Get attribute single
Class
0x3D
Safety Discrete Input Point Object
Instance
i + 1
Where i is the number of the safety
input
Data Type
USINT
Unsigned integer value
Attribute
0x6E
110
Safety Input Alarm Type
0 = No Alarm
1 = Configuration Error
2 = External Circuit Error
3 = Internal Circuit Error
4 = Discrepancy Error
5 = Dual Channel error
If the latch error time has expired, but the safety input is not yet in the safe
state, the alarm will not be cleared. Once the safety input is in the safe state,
the alarm will clear immediately.