Logix System Reaction Time

The following sections provide information on how to calculate the Logix system reaction time.

Simple Input-Logic-Output Chain

This section describes the Logix system reaction time for any simple input-logic-output chain.
Worst Case Reaction Time
Worst Case Reaction Time
The Logix system reaction time for any simple input to logic to output chain consists of the following components.
Item
Description
A
Safety input device reaction time plus input delay time, if applicable.
B
Safety input connection reaction time limit. Read from the Module Properties dialog box in the Logix Designer application, this value is a multiple of the safety input device connection RPI.
C
Controller reaction time. See Safety Task Reaction Time.
D
Safety output connection reaction time limit. Read from the Module Properties dialog box in the Logix Designer application, this value is a multiple of the safety task period.
E
Safety output device reaction time.

Logic Chain Using Produced/Consumed Safety Tags

This section describes the Logix system reaction time for any input to controller A logic to controller B logic to output chain.
Reaction Time with Produced/Consumed Safety Tags
Reaction Time with Produced/Consumed Safety Tags
The Logix system reaction time for any input to controller A logic to controller B logic to output chain consists of the following components.
Item
Description
A
Safety input device reaction time plus input delay time, if applicable
B
Safety input connection reaction time limit
C
Safety task period plus safety task watchdog time for controller A
D
Produced/consumed safety connection reaction time limit
E
Safety task period plus safety task watchdog time for controller B
F
Safety output connection reaction time limit
G
Safety output device reaction time
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