Changing the serial connection speed for ActiveSync connections

CESD-C-0025

Applies To:

  • Windows CE 2.0, SP1
  • Handheld PC Professional, SP1
  • Handheld PC 2000
  • Windows CE 4.0, 4.1, 4.2 .net
  • Windows CE 5.0

Overview:

In the default Operating System configuration for most H/PC class devices, the OEM has left the Serial port baud rate set to the default 19,200 bps. This article discusses how to increase the connection speed when synchronising with ActiveSync.


More Info:

When connecting a Handheld PC to Microsoft ActiveSync version 3.0 or higher, the desktop PC's serial ports will be automatically configured ad-hoc to match the data baud rate of the connecting H/PC.
Windows CE Services does not include these capabilities. If you are still using Windows CE Services 2.0, 2.1 or 2.2 you can upgrade to any version of ActiveSync to benefit from this functionality.
ActiveSync 3.8 is recommended and supports all devices from Windows CE 2.0 and higher.

All RS232 serial ports are designed to comply to the same data transmission standards. The RS232 standard allows for a maximum transfer rate of 115.2 Kbps (115,200 BPS). The proprietary port type on your Handheld PC, despite not using a regular DB9 connector is designed to comply with the standard.
Unlike with ActiveSync, the H/PC's baud rate setting must be manually specified. With the release of Windows CE 2.0, all Handheld PC's were quipped with baud rate profiles, specifically configured for use with the host PC client.

To change the speed of the serial communication between the host PC and the H/PC when using ActiveSync, you need to change the connection mode to the 115.2 Kbps profile.


How-to Guide:

Windows CE was designed to make synchronisation connections using a system similar to, but isolated from the Remote Networking layer. Synchronisation connections over serial should be initiated from the PC Link application and not from Remote Networking.

To select the communications profile used by PC Link

  1. Tap Start
  2. Select Settings and load the Control Panel
    Open Control Panel
  3. Double tap the Communications icon to launch the Communications applet
    Change Communications Properties
  4. Open the PC Connection tab
  5. Tap the Change... button
  6. From the Connect to desktop computer using: drop box, select the communications profile you wish to use
    Select Serial Port

The default, ActiveSync designed profiles are prefixed with the ' character. Most serial users should select the SerialPort @ 115K option. There are some known circumstances with older Windows CE 2.0 devices where the port is not always able to reliably create a 115.2 Kbps connection. If after several attempts your H/PC is unable to create a connection, or you notice reliability issues with the stability of the connection. Reduce the connection profile to SerialPort @ 57600.