LandCell CDM819s User Manual - page 7
2.1 Fast-Track: Circuit Switch Data (CSD) Call Setup
1. Connect the modem to an active COM port on a PC with an RS-232 9 pin straight
through cable.
2. Attach the antenna and power connector.
3. Connect with a Hyper-Terminal session set to 115,200, 8 Bits, No Parity, 1 Stop Bit, and
Hardware Flow Control enabled, the default speed of the modem.
4. If the modem has not been activated, activate the modem. See Section 2.3 and the
Appendix for information specific to your carrier.
5. Confirm the Version of Firmware installed in the Module with an AT+GMR command.
Please note the firmware version, i.e. LF1009, LF10092 or LF10093.
6. Change the Baud Rate to your required speed, i.e. 9600. AT+IPR=9600. Disconnect
HyperTerminal, change the baud rate to 9600 and reconnect. The baud rate change is
persistent through power-cycles.
7. Confirm contact with modem using AT+GSN this prints out the ESN of the modem (i.e.
+GSN: 45263AF4). If you get an Error or no communication, go to the section 2.4
Troubleshooting Communications with the Modem.
8. To auto-answer calls set ATS0=1 A value of ATS0=1 sets the modem to answer on the
first ring, where ATS0=0 disables the auto-answer feature. (Note this is a letter S
followed by a Zero)
9. ATS0=1 is persistent through power-cycles if you have the LF10092 or LF10093
firmware. If the module firmware is LF1009 then the connected device must initialize the
modem with ATS0=1 on power-up (see step 11).
10. Set the modem to answer/terminate incoming Asynchronous Data Calls; AT$QCVAD=4.
11. This is persistent through power-cycles if you have the LF10092 or LF10093 firmware. If
the module firmware is LF1009 then the connected device must initialize the modem with
ATS0=1$QCVAD=4 on power-up in order to auto answer an incoming CSD call on the
first ring.
12. The default value for Carrier Detect is AT&C2, which is set to be always on, but to wink
when there is a change in the connection state to the cellular network. A value of AT&C0
sets CD to always be on. A value of AT&C1 sets Carrier Detect (DCD) to follow its
connection state to the Cellular Network, The yellow LED will turn on when connected to
the Carrier, and turn off when not connected. Changes from the default value are not
persistent through power cycle. If you need a different value than the default value your
connected device will need to initialize the modem with your required value on power-up.
13. The default value of DTR is AT&D2, which returns the modem to command state on an
ON-to-OFF transition of DTR with AT&D2. A value of AT&D0 ignores DTR, a value of
AT&D1 enters online command state upon an ON-to-OFF transition of DTR. Changes
from the default value are not persistent through power cycle. If you need a different
value than the default value your connected device will need to initialize the modem with
your required value on power-up.
14. To confirm your settings, do an AT&V. This will print out about 10 lines of text with all the
register values.
15. Verify that you have good signal strength, AT+CSQ?. A typical reply is +CSQ? 19,99.The
signal strength ranges from 0 to 31, the higher the number the better the signal.
16. Set the modem for verbose result codes, with ATV1, this displays result codes as Words,
ATV0 displays result codes as digits.