SMS and MMS with the Sierra Wireless Compass 885 USB Modem

The Sierra Wireless Compass 885 USB Modem is a very good modem to use with NowSMS to send and receive SMS and MMS messages.

This modem is readily available in the United States, as AT&T sells it as the “AT&T USBConnect Mercury”.

While this modem works extremely well with NowSMS once it is installed, it can be very difficult modem to install. The reason for this is because the primary market for this modem (and other USB modems) is to provide internet connectivity.

If you’re looking at using this modem (or a similar modem) with NowSMS, it’s probably best not to purchase the modem from the mobile operator with a data plan. When you do this, they are assuming that the primary use of the modem is internet connectivity, and NowSMS will not use the modem for that purpose. Often these data plans don’t even have SMS or MMS services enabled.

If you purchase this modem unlocked, it is recommended that you do not use the AT&T branded drivers, but instead use the generic Sierra Wireless drivers. These drivers can be downloaded from http://www.sierrawireless.com/support, specifying “Others” as the “Carrier”.

Install these drivers before installing the modem in your PC. When installing the modem, tell Windows that it can find the drivers in the “Program Files\Sierra Wireless Inc\TRU-Install\Drivers” directory.

Unfortunately, when you attempt to add the Sierra Wireless Compass 885 USB Modem to NowSMS, you will most likely encounter the error message “Modem does not properly support command for sending SMS (AT+CMGS)”.

Or, with older versions of NowSMS, the modem will add correctly, however any attempt at sending SMS messages will result in the error “ERROR -Modem Response (1): OK”.

These errors happen because the driver software for the Sierra Wireless modems actually installs several virtual COM ports for communicating with the modem.

One of these COM ports can be used for sending/receiving SMS messages, while the other COM port can only support data/internet connectivity.

With the 885 modem, multiple virtual COM ports are installed by the Sierra Wireless software. However, a Windows modem driver is installed for only one of these COM ports, so when you select “Sierra Wireless HSPA Modem”, you are connecting to a COM port that only supports data/internet connectivity, not SMS connectivity.

To be able to send/receive SMS messages, it is necessary to identify the other COM port.

To identify the COM port, go into the System applet in the Windows Control Panel, and access “Device Manager”. In the “Ports (COM & LPT)” section, you will find a port labeled “Sierra Wireless AT Command Port (UMTS)”, followed by a COM port number such as COM24.

Once you have identified the COM port number, it is possible to add the modem to NowSMS by referencing the COM port number directly.

However, if you use the COM port directly in NowSMS, you won’t be allowed to configure the modem for sending and receiving MMS. It will support SMS only.

The simple way to enable support for sending/receiving MMS is to manually install a Windows Modem driver for this COM port. This can be done through the “Phone & Modem Options” applet in the Windows Control Panel. We recommend that you manually select the modem driver, rather than having Windows detect the modem. For best results, use the “Standard 33600 bps Modem” driver.

After installing this Windows modem driver, configure NowSMS to use the “Standard 33600 bps Modem” to connect with the Sierra Wireless 885, instead of using the direct COM port reference.

For general information on configuring NowSMS to send and receive SMS and MMS messages with a GSM modem, such as the Sierra Wireless Compass 885, please see the NowSMS Quick Start Guide at https://nowsms.com/doc/quick-start-guide.