Chapter 3 – Troubleshooting

GSM/GPRS FAQ on the IP Stack

Whenever I send the # commands, I receive an error.

You must enable the stack before the modem will accept the # commands.

‘AT+WOPEN=1’ will enable the stack and ‘AT#VVERSION’ will display the version of the stack.

If you receive an error when sending ‘AT+WOPEN=1’, then you may not have the stack present on the modem.

How do I know if I have the stack?

Use the ‘AT+WOPEN=1’ command. If it returns an error, then the stack may not be present in the modem.

How do I make a GPRS connection using the stack?

Send: AT#GPRSMODE=1 (sets the modem to GPRS mode) AT#APNSERV=”APN” (sets the APN for the modem to connect) AT+CGATT=1 (attaches the modem to the GPRS network) AT+CGREG=1 (registers the modem onto the GPRS network) AT#CONNECTIONSTART (to start the connection) AT#CONNECTIONSTOP (to stop the connection)

I have T-Mobile. When I try to establish a GPRS connection using the stack, the modem doesn’t connect. It seems like the modem gets reset.

Check the firmware version: ‘AT+CGMR’.

Version 640b had a bug that caused the modem to reset when using a non-authenticated account. Authenticated accounts such as AT&T and Cingular work OK. Firmware version 641a fixes this issue.

You will have to send the modem in for a firmware upgrade. Send it to the attention of the MultiTech Repairs Department. Include a letter stating the problem and that you need the version 641a firmware.

How do I make a connection to my ISP using the stack?

ƒMake sure you have CSD service.

ƒSend: AT#GPRSMODE=0 (sets the modem to GSM mode) AT#DIALN1=”ISP’s access #” AT#DIALSELECT=1

AT#ISPUN=”username”

AT#ISPPW=”password”

AT#CONNECTIONSTART

AT#CONNECTIONSTOP

I can’t use the stack to connect to the GPRS network. I keep getting CME errors.

Check the CME error number in the AT Command Reference Guide.

Make sure the modem is attached and registered with the ‘AT+CGATT?’ and ‘AT+CGREG?’ commands.

Make sure the APN is correct with ‘AT#APNSERV?’.

Can I ping the modem when I have a connection established with the stack?

Yes, but you must be connected to an APN or server that provides public IP address and is not blocked by a firewall.

Can I ping out using the stack?

Yes, but you must have the firmware version 641a or higher.

The command is ‘AT#PINGREMOTE=”<address to ping>”’ and ‘AT#PING’ to start the ping.

You must have a connection established with the stack in order to use the ping commands.

Does the stack support UDP?

Yes, but only on the firmware version 641a and above.

Multi-Tech Systems, Inc. MultiModem® GPRS with USB User Guide

35

Page 35
Image 35
Multi-Tech Systems MTCBA-G-UF2, MTCBA-G-UF1 manual GSM/GPRS FAQ on the IP Stack

MTCBA-G-UF1, MTCBA-G-UF2 specifications

Multi-Tech Systems has long been a leader in the field of communication technology, offering a wide range of devices and solutions designed to enhance connectivity for various applications. Among their notable products are the MTCBA-G-UF2 and MTCBA-G-UF1 devices, which are designed to provide efficient and reliable connectivity for IoT applications and industrial use.

The MTCBA-G-UF2 and MTCBA-G-UF1 are advanced cellular modem solutions that support both 3G and 4G LTE networks. These devices are built to offer robust performance, ensuring seamless data transmission across various environments. The MTCBA-G-UF2 comes equipped with dual SIM capability, which enhances connectivity by allowing users to switch between different cellular networks effortlessly. This feature is particularly advantageous for mission-critical applications where consistent connectivity is essential.

Both models feature Multi-Tech’s renowned easy-to-use interface, which simplifies the installation and configuration process. The devices support various communication protocols, making them versatile options for a wide range of applications, including remote monitoring, telemetry, and fleet management. Their compact design ensures they can be integrated into various systems without occupying significant space.

One of the standout characteristics of both the MTCBA-G-UF2 and MTCBA-G-UF1 is their support for advanced security features. The devices implement robust encryption protocols, ensuring that data transmitted over cellular networks is safe and secure from unauthorized access. This is especially critical for businesses that handle sensitive information or operate in regulated industries.

Additionally, these modems are designed to withstand harsh environmental conditions, making them suitable for outdoor use. With wide operating temperature ranges and rugged enclosures, they are capable of functioning in various climates and situations. Furthermore, Multi-Tech Systems provides extensive support and documentation, enabling users to leverage the full potential of their devices.

In conclusion, the Multi-Tech Systems MTCBA-G-UF2 and MTCBA-G-UF1 are powerful solutions tailored for reliable and secure cellular connectivity. With their rich set of features, including dual SIM support, multi-protocol functionality, and secure data transmission, they are ideal choices for various IoT applications and industries requiring dependable communication solutions. These modems exemplify Multi-Tech's commitment to innovation and reliability in the ever-evolving world of connected devices.