User guide

Chapter 2: Getting Started
Multi-Tech Systems, Inc. CallFinder GSM Cellular Gateway 13
A6. At the HyperTerminal prompt, type AT and press Enter.
The CallFinder will return the response OK, thus confirming that the CallFinder is communicating
with the command PC.
At this point, the communications program is set up for steps 3B and 3C below.
3B. Verify Signal Strength
B1. In the command window, type AT+CSQ
B2. The modem responds with the received signal strength (rssi) in numeric form.
The meaning of the number returned is shown in the table below.
Signal Strength
–
RSSI
20 - 31 High signal (three LEDs lit)
10-19 Medium signal (two LEDs lit)
4-9 Low signal (one LED lit; CallFinder can operate with this level of signal)
0-3 Insufficient signal (no LEDs lit)
99 No signal (no LEDs lit)
3C. Checking Network Registration and Roaming Status
Use this command to verify that the wireless CallFinder modem has been registered on a wireless
network.
C1. In the command window, type AT+CREG?
C2. The modem will respond in one of the following ways:
Network Registration Verification
V
alue Network Registration Status
+CREG: 0,0 The modem is not registered on any network
+CREG: 0,1 The modem is registered on the home network
+CREG: 0,5 The modem is registered on a network and it is roaming
Note: If the CallFinder modem indicates that it is not registered, verify the signal strength to
determine if the problem is the strength of the received signal.
When you have completed your configuration and checking of the CallFinder, exit from the
communications program.
Step 4. A Reminder about FXO/FXS Status
So far we have not mentioned the FXS or FXO interface connectors on the back panel of the Wireless
CallFinder. This issue is addressed in Chapter 4. Be aware that the CallFinders are set to FXS at the
factory. Note also that in order to use the FXO interface connector you must re-set the interface using a
communications program (like HyperTerminal). It does not work merely to connect the CallFinder to a
telephony device using the FXO connector. The internal setting must be set to match the connector that
you use.