Good evening,

I have doubt about profisafe and failsafe meaning. What are the uses of this modules? 

You can start by studying the material behind the below link. The word Fail-Safe is used in Siemens safety modules, and they are a part of PROFIsafe

Safe communication

Hello Sampathkumar;

"Failsafe"  is a designation based on IEC 61508 (alternatively on ISO 13849-1) promoting the use of automation systems in Safety systems. Safety refers to the detection of unsafe situations in a process, followed by placing the machinery of the process in a "safe" state, where personnel will not be at risk of injury or death. IEC 61508 uses Intrinsic Safety level designations SIL 1 to SIL 3 to classify the increasing complexity of the safety design; ISO 13849-1 does the same with Performance Levels PLa to PLe.

Profisafe is a specialized communication profile allowing the use of Safe communications over Profibus and Profinet:

"PROFIsafe(PROFIBUS safety or PROFINET safety) is a safety communication technology for distributed automation. Its specification for PROFIBUS DP and PROFIBUS PA was published first in 1999. Extensions for theEthernetbased PROFINET IO followed in 2005.

The IEC 61508 standard specified how microcontrollers and software can be used in safety automation."

https://en.m.wikipedia.org/wiki/PROFINET

 Hope this helps,

Daniel Chartier