RAS Error 652 with US-Robotics 14400 Sportster

The information in this article applies to:

• Microsoft Windows for Workgroups version 3.11

SYMPTOMS

After you configure the Windows for Workgroups Remote Access Service (RAS) client with a US-Robotics 14400 Sportster modem, or some Gateway Telepath and internal modems, for call-back from a RAS server, the modem fails to reinitialize in call-back mode and the following error message appears:

   Error 652: Unrecognized text response received from the device.
   Make sure the device you selected in Setup matches your modem.

CAUSE

This problem occurs because the RAS client software in Windows for Workgroups version 3.11 does not keep the Data Terminal Ready (DTR) signal state low long enough for the modem to release the line. In this case, DTR was in the low state for approximately 1 millisecond. The US-Robotics 14400 Sportster modem requires the DTR to be in the low state for at least 5 milliseconds.

STATUS

Microsoft has confirmed this to be a problem in Windows for Workgroups version 3.11. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

The US-Robotics 14400 Sportster modem is manufactured by US-Robotics, a vendor independent of Microsoft; we make no warranty, implied or otherwise, regarding this product's performance or reliability.