Chapter 4 – Safety
Multi-Tech Systems, Inc. MultiModem GSM/GPRS User Guide 21
Chapter 3: Troubleshooting

Troubleshooting Examples

Situation A: The modem does not answer through the serial link

If the Wireless MultiModem does not answer through the serial link upon an attempted transmission of
data or voice signals, see the table below for possible causes and solutions.
Solutions for ‘no connection through serial link’ situation
If the
modem
returns …
Then ask … Action
Is the modem
powered correctly?
Provide a power supply in the range of 5 to
32Vdc.
Is the serial cable
properly connected
to the modem and
PC sockets?
Connect cable per step 5 of the ”Electrical
Installation and Configuration” procedure. Verify
cable pinout per”RS232 15-Pin Connector Pinout”
table, esp Rx & Tx connections. Verify reception
& transmission.
Is the
communication
program properly
configured?
In communications program, verify that modem
parameters have been set to the values shown
here:
Data bits = 8
Parity = none
Stop Bits = 1
Baud = 115200 bps
(nothing)
Is another program
interfering with the
communication
program?
Close any such application program.