Using the MultiTech CDMA Cellular Modem – Application Note #17 – Page 2 of 4
With power and the RS-232 cable connected the PWR and CD LED’s should be on steady. If there is
CDMA signal available, the MultiModem should register (after a minute or two) with the network and the
LS LED should be flashing.
Using the Hyperterminal program at the computer to which the Wireless MultiModem is connected via
RS-232, it is now possible to issue AT commands to test and configure the MultiModem. Note when
Hyperterminal makes the “call” the TR LED will now be on steady.
To check Signal Strength use the following:
AT+CSQ Signal Strength Verification
This will return the following values with the response syntax: +CSQ: <rssi>,<fer>
<rssi> is the Receive Signal Strength Indicator: This parameter represents the total RF received signal
power from the base station(s) the mobile sees. A Signal strength of 10 – 31 is sufficient , 0 - 9 is weak
or insufficient, and 99 is insufficient.
<fer> is the channel frame error rate. It is not used currently and always returns a value of 99.
This check can be done without a service contract with Verizon.
To check Network Registration Verification use the following:
AT+CREG Network Registration
Verification
This will return one of the following values with the response syntax: +CREG: <0,stat>
0: not registered, MS is not currently searching for a new operator.
1: registered, home network.
2: not registered, MS currently searching for a base station.
4: unknown.
5: registered, roaming
This check can be done without a service contract with Verizon.
If the modem does not register, perform the procedure for Verifying Signal Strength to determine the
strength of the received signal.
To activate the MultiModem with Verizon Account information:
Once a Verizon Wireless account has been obtained (see below for information on obtaining an account),
the MultiModem will need to activated by entering the phone number using the following three AT
commands:
AT+WSPC=1,000000<cr> ;enter the programming code; response from modem should be OK
AT+WMDN=nnnnnnnnnn<cr> ;”nnnnnnnnnn” is your phone number (your MDN);
response from modem should be OK
AT+WCMT=1<cr> ;commit the changes to memory; response from modem should be OK
MultiModem Configuration for use with Campbell MCU Data Acquisition:
Five parameters that must be configured in the MultiModem in order for it to work with a CR10X based
datalogger system are:
1) The RS-232 port’s baud rate referred to as the “Fixed DTE Rate”
2) The RS-232 port’s flow control referred to as the “DTE-DCE Local Flow Control”
3) Auto Answer
4) The type of incoming calls to expect, referred to as “Incoming Call Bearer”
5) The Save Configuration Command
To Set Fixed DTE Rate:
The RS-232 port’s baud rate is set to the required 9600 baud using the command AT+IPR=9600. NOTE:
After this command is issued, it is necessary to change the baud rate in Hyperterminal to 9600 in
order to continue to communicate with the MultiModem. To check the baud rate parameter use the
command AT+IPR?.
To Set DTE-DCE Local Flow Control:
The RS-232 port’s flow control is set to the required None using the command AT+IFC=0,0 where the
first 0 sets the TX flow control to none and the second 0 sets the RX flow control to none. To check the
flow control parameter use the command AT+IFC?.
(24 paginas)
Manymanuals.com
Manymanuals.de
Manymanuals.fr
Manymanuals.it
Manymanuals.pl
Manymanuals.cz
Manymanuals.es
Manymanuals-pt.com
Comentarios a estos manuales