HYDROLOGICAL SERVICES ML1-420, Operation Manual

Hydrological Services Pty Ltd

Data Logger Model ML1-420 

© 

Copyright 

ML1-420  100-34

Issue 1.00  6 Apr, 2011 

Modem Settings 

 
Before the modem is put into service, the following settings should be programmed into the 
modem (in the same way as a PSTN modem). Simply connect the modem to your PC using 
the cable supplied with the modem, and run a program such as WinComLog or Hyperterm. 
Type AT<CR> and you should get an “OK” response. Then set the following commands in 
the modem : 
 

ATE0

Turn off character echo 

AT&C0

DCD is always on 

AT&D0

DTR is ignored 

AT&S0

DSR is always on 

ATS0=2

Auto-answer after 2 rings 

AT&W

Save these settings (they will be restored on the next power up) 

 
Further advanced settings are required for the GSM modem. 
 

AT+IPR=9600

Force 9600 baud communications to Minilog 

AT+CSQ

Determine the signal strength.  Typical Reply : 
+CSQ: 26,0  
(0-10 insuffucient   :   11-31 sufficient   :   99 no measure available) 

AT+CREG?

Determine the registration status.  Typical reply : 

+CREG: 0,0   Not Registered (no signal or SIM card not installed) 

+CREG: 0,1   Registered (home network) 

+CREG: 0,5   Registered (roaming) 

 
Some SIM cards have PIN access. So enter the PIN code as follows, and then turn off the PIN 
requirement. (The PIN must be disabled, as there is no way for the MiniLog to enter a PIN) 
 

AT+CPIN=xxxx

Enter the pin code 

AT+CLCK=”SC”,0,xxxx

Turn off the PIN requirement 

 
The Wavecom Fastrack and Intercel SAM modems both recommend that for continued 
network coverage, they be setup to reset every 24 hours by using the following command : 
 

AT+WRST=1,”024:00”

Reset every 24 hours 

 
The GSM modem should now be ready to connect to the MiniLog with the appropriate cable 
(see the connection diagram earlier in this appendix). 
 
Use WinComLog (Rev2.20 or greater) and enter the phone number of the GSM modem SIM 
card, then press the “Dial” button. (+++ will be sent to the PC modem to get its attention, and 
then the ATDTxxxxxxxx command will be sent to perform the dialling to the GSM modem.) 
You will hear the usual dialling, ringing and connection tones through the modem. When a 
connection has been made, send a simple command like ?<CR> to check that 
communications has been established. When the communications session is complete, press 
the “Hangup” button. (Again +++ will be sent to the modem to get its attention, and then 
ATH to perform the hangup)