Omron NX-SID Series - Safety Reaction Times; Calculating Safety Reaction Times

4 Calculating Safety Reaction Times
4 - 2
NX-series Safety Control Unit User’s Manual (Z930)
4-1 Safety Reaction Times
This section describes the safety reaction times (i.e., the safety response performance) of Safety Con-
trol Units.
For all safety chains, the longest time required to stop moving equipment from when a safety input was
activated must satisfy the required specifications.
A safety reaction time is the time required to turn OFF an output when considering failures and break-
downs. Reaction times are used to calculate the safety distances.
The safety chain is the logical connections that are required to achieve a safety function, including the
safety input device, NX-series Safety Control Units, and safety output device.
This section gives the safety I/O reaction times for the Safety I/O Units.
As shown in the following figure, a safety reaction time is the sum of the safety sensor/switch response
time, safety I/O refresh time, and actuator response time.
The contents of each time element is described in the following table.
4-1-1 Safety Reaction Times
4-1-2 Calculating Safety Reaction Times
Time element Description
Safety
sensor/switch
response time
This is the response time that is required for a safety sensor or switch, such as a light curtain, to
turn OFF. The value is defined for each sensor or switch.
The following values apply when an OMRON Special Safety Input Device is connected to a
Safety Input Unit.
E3ZS/E3FS Single-beam Safety Sensors: 14 ms
D40A Non-contact Door Switches: 6 ms + 0.4 ms x No. of linked Switches
*1
D40Z Non-contact Door Switches: 29 ms
UM Safety Mats: 24 ms
*2
SGE Safety Edges: 24 ms
Safety sensor
/switch response
time
Actuator
response time
Safety input
refresh time
Input
delay
time
Safety output
refresh time
Safety sensor
/switch
Safety Input Unit Safety CPU Unit
Safety I/O refresh time
Safety Output Unit Actuator