Reaction Time - Siemens SIMATIC S7-400 Manual

9.5

Reaction Time

Definition of the Response Time
The response time is the time from an input signal being detected to changing an output
signal linked to it.
Variation
The actual response time is somewhere between a shortest and a longest response time.
For configuring your system, you must always reckon with the longest response time.
The shortest and longest response times are analyzed below so that you can gain an
impression of the variation of the response time.
Factors
The response time depends on the cycle time and on the following factors:
● Delay in the inputs and outputs
● Additional DP cycle times on the PROFIBUS-DP network
● Execution of the user program
Delay in the Inputs and Outputs
Depending on the module, you must heed the following time delays:
• For digital inputs:
• For digital inputs with
• For digital outputs
• For relay outputs:
• For analog inputs:
• For analog outputs:
The time delays can be found in the technical specifications of the signal modules.
S7-400 Automation System, CPU Specifications
Manual, 10/2006, 6ES7498-8AA04-8BA0
interrupt capability:
Cycle and Response Times of the S7-400
The input delay time
The input delay time +
module-internal preparation time
Negligible delay times
Typical delay times of 10 ms to 20 ms.
The delay of the relay outputs depends, among other
things, on the temperature and the voltage.
Analog input cycle time
Response time of analog outputs
9.5 Reaction Time
9-11