Remote Monitoring And Controlling Solutions

Product Details:

This application shows how to set up a simple system for switching and signaling by means of SMS messages. The field of application used as an example is a drink vending machine. At regular intervals, the automatic machine checks:

• The remaining stock of the different types of beverages
• The coin box level
• The cooling system temperature. In addition, unauthorized opening of the front is detected using a sensor.

The automatic machine reacts independently to specific events – such as exceeding/falling below limits – and informs the maintenance staff. Irrespective of that, the automatic machine answers requests that have been received for process values.

This automation problem results in the following details regarding the functions of the solution:

• Sending a message to several subscribers (Broadcast)
• Sending a message with subsequent waiting for acknowledgement (Escalation)

Receiving messages. Depending on the message text,

• requested values are read out of the controller and sent to a mobile phone
• received commands are executed in the controller and a confirmation/error message is sent to the mobile phone.

Sending an SMS message to one parameterizable phone number.

• Process values can be integrated in the message text.
• The send routine can be started from the user program of the controller using a trigger.

The SIMATIC CP 1242-7 modem is the core component of this solution. With the aid of the CP for the SIMATIC S7-1200, short text messages can be sent to any mobile phones and short text messages can be received from these mobile phones. The application example shows how to program the requirements for SMS communication in the user program of the S7-1200 CPU. You can use the functionality fully or partially for your own requirements or customize it.

A SIMATIC CP 1242-7 (2) is connected to a SIMATIC S7-1200 controller 1211C (3) via the bus interface. A SIM card (5) is inserted in the GSM/GPRS modem and an ANT 794-4MR quad-band GSM/GPRS antenna (4) is used for the connection to the air interface. The power supply of all components is provided via a SIMATIC PM 1207 power module (1).