10 RELAY GSM board is designed on Renesas Microcontroller and SIM 800C SIMCOM GSM.
It supports all models SIM except JIO 4G LTE.
Individual relays can be controlled ON, OFF by sending SMS.
Master mobile can be registered by simply sending SMS 
#X
Return confirmation message arrives on successful registration.
Now relays can be switched  ON, OFF by sending SMS
#A1   Relay 1 ON
#A0  Relay 1 OFF
 
#B1   Relay 2 ON
#B0  Relay  2 OFF
 
#C1   Relay 3 ON
#C0  Relay 3 OFF
 
#D1   Relay 4 ON
#D0  Relay 4 OFF
.........
#I1   Relay 9 ON
#I0  Relay 9 OFF
 
#J1   Relay 10 ON
#J0  Relay 10 OFF
 
#SPN  to know the Registered numbers
#STS  to know the status of Relays
 
#L1  to switch ALL RELAYS ON one by one
#L0  to switch ALL relays OFF.
 
DTMF mode is used by calling to the SIM number on board.
After a beep sound you can key in the Relay number, for e.g  1 to switch relay 1 ON.
Again press 1 to switch OFF.
Single Beep sound for ON & Double Beep sound for OFF
Relay 10 control is not supported in DTMF.
 
Timer mode switching is possible.
#STA=xx  for seconds
#MTA=xx for minutes
for e.g #STA=10   Switches ON the A relay for 10 seconds and then goes OFF.
Related message in timer mode is sent to master .
#MTA=5  switches ON the A relay for 5 minutes and then goes OFF.
 
There are 7 INPUT TRIGGERS  IN1 to IN7
12V is extended to screw connecter.This 12v when looped externally to IN1 , then input 1 is triggered and message sent to master.
This message can be modified by User.
#INS1=xxxxxx
#INO1= xxxxx
upto 20 charcters allowed.
for second input use =#INS2=xxxx,  #INO2=xxxx