Md740-1 Gprs Modem - Siemens SIMATIC NET SINAUT ST7 System Manual

Introduction to the SINAUT ST7 system
2.5 Mobile wireless components
The following figure shows further details of the modem module.
s
Figure 2-14
2.5.2

MD740-1 GPRS modem

Using the MD740-1 GPRS modem, a TIM can establish a permanent connection between a
station and control center using the GPRS service of a GSM mobile wireless provider. Since
the connection is always online, data can be sent as soon as it becomes available.
The control center must be permanently reachable from the GPRS network, for example
connected over a dedicated line to the GPRS provider or over a permanent connection to the
Internet, for example over DSL. A direct GPRS connection from GPRS modem to GPRS
modem is not possible. Direct data exchange between two SINAUT ST7 stations that both
communicate over GPRS is, however, possible over a TIM module in the control center.
Since the data transmission from the GPRS provider to the control center is often over the
Internet, the MD740-1 has an integrated VPN router and a firewall. This allows GPRS
connections with optimum security to be established between the station and control center.
The maximum data transmission speed with GPRS is 54 Kbps.
The MD740-1 can be attached to the Ethernet port of a suitably equipped TIM module (all
TIM 3V-IE variants). It can be installed on a 35 mm standard rail.
66
SET
Connectors of the MD720-3 modem
SINAUT ST7 Station control system - System Manual
System Manual, 05/2007, C79000-G8976-C178-06