NSDictionary *params = @{@"par1": @"value1",
@"par2": @"value2"};
AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
[manager.requestSerializer setTimeoutInterval:25]; //Time out after 25 seconds
[manager POST:@"URL" parameters:params success:^(AFHTTPRequestOperation *operation, id responseObject) {
//Success call back bock
NSLog(@"Request completed with response: %@", responseObject);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
//Failure callback block. This block may be called due to time out or any other failure reason
}];