UNITRONICS

GPRSGPRS

GPRS - General Packet Radio Service

GPRS is packet based wireless communication service offered by some

GSM cellular providers.

GPRS promises continuous connection to the Internet via cellular

network for mobile phone, computer users and PLCs.

With GPRS connection, the user pays for transferred Kbytes and not for

call time. In theory GPRS packet-based services cost users less than

circuit-switched services.

About GPRS

After GPRS connection established between PLC and PC you can use

Unitronics software to:

Download, upload, and edit the controller program.

Read and write data to/from controllers via Remote Access or other

Unitronics' communication utilities.

Log PLC data via the DataXport utility.

GPRS & Unitronics OPLC

Connect to SCADA via UniOPC server or Modbus

establish connection between Unitronics OPLCs and transfer data

(using for example MODBUS protocol).

GPRS & Unitronics OPLC

Before We start…

Requirements:

GSM Modem which supports GPRS functionality. Currently Vision

OPLC can work with list of modems

GPRS service must be supplied by the user's cellular service provider

The GPRS modem must be prepared to PLC side

PC with direct internet access using public IP

Before exchanging data, OPLC must register to the provider’s cellular

network.

Registration

After successful registration the controller will receive IP

address. This address usually is temporary – each time you

register you receive new IP.

Registration

The IP address is one of the provider’s LAN. Usually, without

special agreement with the provider, you cannot access this

address from outside LAN.

That’s why the standard procedure is, when the controller calls

the remote PC.

The remote PC needs to be already in Listen mode.

Sometimes you will want to exchange data between two controllers or

controller and other device, located in the same LAN.

In some cases, after agreement with the provider, it’s possible to access

the controller from outside cellular LAN.

In this cases the OPLC can be configured to Listen mode.

Listen

When we want to end the data transfer with specific device, we perform

End Call.

If our device is in Listen mode, we can Stop Listen.

We can end the session with Unregister from network.

End connection

Thank you!