Product specifications

GSP-1620 Modem Overview

2-4 80-99240-1 Rev. D

Figure 2-3 depicts a typical use of the GSP-1620 modem for a

SCADA application using asynchronous data.

Figure 2-3 Typical Modem SCADA Application Using Asynchronous Data

For asynchronous data connections, the GSP-1620 modem

can dial or be dialed by a host modem, connecting through the

Globalstar Satellite Communications System and the PSTN.

Modem Application Characteristics

For either packet or asynchronous connections, as shown in

Figure 2-2 and Figure 2-3, modem applications have the

following basic characteristics:

• The GSP-1620 modem serves as the DCE (data

communications equipment) at the remote site. It

functions essentially as a 9600 bps full duplex satellite

modem. The modem uses typical Hayes AT commands

(see Chapter 4, AT Commands). Standard RS-232

Satellite

Globalstar

Gateway

Server

GSP-1620

Modem

SCADA Terminal

Control Port

Data Port

DTE

DCE

Host

Outdoor Antenna

PSTN

Gateway IWF Modem

Host Modem

Remote