BISTANIKA SDN BHD

Tuesday, September 4, 2012

Wireless Data Communication via GPRS with S7-1200 and CP 1242-7, Scenario 2, Cross communication

The task in general termsThis application refers to the topic of wireless communication between distributed automation stations via GPRS (M2M communication), with and without a control center. The document is broken down into several variants which differ with regard to the transmission protocols and the different hardware components used in the remote stations. It is aimed at providing a selection aid, so as to find the best variant based on the technical parameters and with consideration to the conceptual requirements. Furthermore, this application description focuses on the provision of helpful advise for the configuration and parameter assignment of the selected variant. The task in concrete terms
Each variant is explained in greater detail on the basis of a specific application example.

Variant 1:
The filling level of an elevated water tank shall be transmitted to a pump station. For the purpose of remote control and remote visualization, the two distributed stations are already linked to a control center.

Variant 2:
The power supplier and operator of a wind farm shall be able to adjust the output of his wind farm to the current consumption situation in the electricity grid. This shall be effected by means of an I/O connection between several wind turbines and a switching station. There is no control center involved in this system.

Variant 3:
Several oil production fields are equipped with a series of controllers. They are used for simple automation tasks like the control of pumps, for example. Now, the filling level information from all oil production fields shall be transmitted to a higher-level controller with higher performance capacity, so as to enable global releases for oil production. There is no control center involved in this system.

Solution
The variants discussed in this application example (configuration example CE-X21, scenario 2) show, how the given tasks can be solved with the help of SIMATIC components. The central component in this solution is the GPRS modem SIMATIC CP 1242-7. With the help of CPs for the SIMATIC S7-1200 controllers, telegrams can be sent to other CPs or to other IP-capable network participants over a GPRS connection.
A SIMATIC CP 1242-7 GPRS (2) is connected to a SIMATIC S7-1200 controller 1211C (3) via the bus interface. The GSM/GPRS modem is equipped with a SIM card (5) and connection to the air interface is realized with a quad band GSM/GPRS antenna type ANT 794-4MR (4). All components are supplied with power by a SIMATIC PM 1207 power module (1).

Depending on the specific variant, a further SIMATIC S7-1200 controller in combination with a SIMATIC CP 1242-7, or a SIMATIC S7-300 controller with UMTS/GPRS modem SCALANCE M 873-0 are used.
A UMTS/GSM modem SCALANCE M873-0 (2) is connected to a SIMATIC S7-300 controller 315-2 PN/DP (4). The UMTS/GSM modem is equipped with a SIM card (5) and connection to the air interface is realized with a quad band antenna type ANT 794-4MR (1). All components are supplied with power by a SIMATIC PS307 power module (3). The S7-300 controller is provided with a SIMATIC micro memory card.