GPRS/GSM MODEM/WEB BASED SCADA
Our modem which is used to communicate with the PLC via RS232 serial interface . MODEM is Program in such a way that storing the static IP of the server which is used for connecting the modem to the server for data transmission . MODEM have their own unique UNITID, so that we can distinguish it with all other MODEM data. We also configured the sending interval of data to the server and also set the MODBUS command . MODEM is connected to the PLC via RS232 on the other hand it also communicate with SERVER via GPRS.
When the MODEM starts It will activate its GPRS using the SIMCARD (GPRS ACTIVATED) which we insert before giving power supply , using GPRS modem is connected to the SERVER (STATIC IP) shown below.
THE CLIENT SHOWS THAT THE MODEM CONNECT TO THE SERVER SUCCESSFULLY
After a particular time period that we previously set in the modem configuration the Modbus command that is stored in the modem itself is sent to the PLC via RS232 . In response of the Modbus command the PLC generates its Response as per the command sent by the modem and then sent it back to the Modem. In the MODBUS command we actually read the holding register of the PLC . Now Modem has the response which is given by PLC This is sent to the server by the Modem using GPRS .
RESPONSE OF PLC TO THE SERVER SENT BY MODEM
The response is then stored in a database , Every UNIT has their own separate table which we can use for further inquiry .
DATABASE SHOW THE SEPARATE RAW FOR ALL UNIT ID
Using the database we can correlate it to the SCADA.
SCADA ON THE SERVER
Now if we want to ON and OFF any digital input and digital output we can set it directly from the SCADA as shown below (because our modem is already connected to the server) it is used to control the PLC from the server with the help of SCADA and GPRS through which our modem is connected to the server.