Specifications

APPLICATION NOTE

Using the SUTRON RADAR LEVEL CONTROLLER (RLR-0002-1) with a MULTI-MODEM GPRS

(Wireless Modem MTCBA-G-F4)

2.2.4 Configuring the GSM Modem

In order to configure the GSM modem, you must use a terminal application such as

HyperTerminal in Windows. To open this program, go to: Start>All

programs>Accessories>Communications>Hyper Terminal.

AT commands can be used to operate, configure and query the GSM modem. A reference guide

is included on the Multi-Tech Web site. AT commands used in this application notes will be

necessary to configure the GSM modem for our purpose.

After we power up and connect the modem to the COM port in your PC, we should be able to

communicate to the modem via Hyper Terminal. The parameters of communication for the Port

Settings Tap in the Hyper Terminal configuration are:

• Bits per second: 9600

• Data Bits: 8

• Parity: None

• Stop Bits: 1

• Handshaking: Hardware.

At this point we should be able to communicate with the GSM modem. To verify it, we can type

the command “AT&V” (then ENTER), this command will show the current settings of the GSM

modem.

The GSM Modem programming depends on the type of interface selected in the setting of the

radar level sensor (RLR-0002-1). Two modem interfaces are available to the radar level sensor:

Command-line and MODBUS.

In the following sections we will explain the necessary configuration for the GSM modem and

the radar level sensor in each interface: Command-line and MODBUS.

2.3 Command Line Interface

This section describes how to configure both the GSM modem and Radar Level Sensor for

Command-Line interface. The MODBUS mode must be disabled in the radar level sensor to

communicate via Command-line interface. This configuration will allow you to use Hyper

Terminal to remote access the data in the radar.

2.3.1 GSM Modem AT commands-Command Line.

The following AT commands are required to program the GSM modem. First, you have to

connect the GSM modem to a PC and configure the modem using Hyper Terminal in Windows.

You must use a RS 232 serial cable to connect the GSM modem to a PC. This configuration

will allow you to access the command line interface in the radar via Hyper Terminal. Type a

<Enter> after each command.