Sim900 sleep & awake

Im working on a project where I want to sleep my sim900.

So my code is:

#include <Time.h>
#include <TimeLib.h>
#include <SoftwareSerial.h>
#include <TimeAlarms.h>
#include <dht.h>

dht DHT;
#define DHT11_PIN 5
char number[]="+mynumber";
boolean started=false;
SoftwareSerial sim900(9,10);

void setup(){
  Serial.begin(9600);
  delay(10000); //Allow time for the SIM to register
  Alarm.timerRepeat(10800, MainAlarm);

void loop(){
  Alarm.delay(10);
}

void MainAlarm(){
  sim900.print("AT\r"); //wake up<<<<<<<<<<<<<<<<<<<<<<<WAKE UP
  delay(2000);
  Serial.println("Main Alarm...");
  int chk = DHT.read11(DHT11_PIN);
  Serial.print("Temperature = ");
  double temp = DHT.temperature;
  Serial.println(DHT.temperature);
  Serial.print("Humidity = ");
  double hum = DHT.humidity;
  Serial.println(DHT.humidity);
  sendData(temp,hum);
}

void sendData(double temp, double hum){
  sim900.begin(9600); 

  static char outTempStr[15];
  static char outHumStr[15];
  String tempString = dtostrf(temp,5,2,outTempStr);
  String humString = dtostrf(hum,5,2,outHumStr);

  delay(5000);
  sim900.print("\r");
  delay(1000);
  sim900.print("AT+CMGF=1\r"); //text mode
  delay(1000);
  sim900.print("AT+CMGS=\"+mynumber\"\r");
  delay(1000);
  sim900.print("Temp=" + tempString +  "Hum=" + humString + "\r");
  Serial.println("sent!");
  delay(1000);
  sim900.write(0x1a);
  sim900.println(char(26));
  Serial.println("done!!");
 //Now that it is sent, sleep the sim900
  sim900.print("AT+CSCLK=2\r"); //sleep mode <<<<<<<<<<<<<<<<<<SLEEP
}

and I would add:

AT+CSCLK=2

which sleeps it. Now it should be woken up with something like:

AT

And then I continue my code execution. Can anyone tell me how to check if its gone to sleep?

Can anyone tell me how to check if its gone to sleep?

Listen carefully. If it starts snoring, it's asleep.

Hahahaha!

I mean, I guess I can check the current draw but I wanted to know if there is a led Blink pattern I can watch out for?