Installing and putting a SINAUT modem into operation
5.3 GSM/GPRS modem MD720-3
Station control system
184
System Manual, 07/2009, C79000-G8976-C178-07
5.3
GSM/GPRS modem MD720-3
Introduction
This section describes the design of the MD720-3 modem, its connectors and display
elements.
5.3.1
Displays and connectors
The following figure shows the front view of the MD720-3 modem.
1
2
3
4
5
6
Connector for 24 V DC power supply
SET button for service functions
Antenna connector
Display elements
9-pin connector X1 (RS-232 female)
Order number of the modem
Front view of the MD720-3
modem
LED displays of the MD720-3
The following table summarizes the meaning and activity of the three LEDs on the front of
the modem.
Table 5- 1
Meaning of the LEDs on the front of the MD720-3
LED
Status
Description
S, Q, C together
Flash on and off in sequence (fast)
Flash slowly (in sync)
Flash on and off in sequence (slow)
Flash fast (in sync)
Booting
Service mode
Update
Error
S (Status)
Flashes slowly
Flashes fast
Waiting for PIN input
PIN error/ SIM error