The CRD3301 is a charging and communication cradle for the OPR3301, and OPI3301. A newer revised version is the CRD3301B.

Wired interface

The Cradle can support two (2) interface communication types to the host PC. It supports RS232C and USB HID. CRD3301B Supports RS232, USB-HID and USB-VCP (Virtual COM Port) Interface identification is done automatically by monitoring the power of the interface.


The cradle must be rebooted before new dip switch settings can take effect.


The following functions can be set with DIPSW on the bottom of this unit:

It is for future function expansion.

You will be able to connect without authentication.

It will be able to connect with Bluetooth devices other than OPR - 3101.

Set when there is no DTR signal on the host side equipment.

The contents of FLASH are returned to the initial state.

In the ON state, the unit enters a download mode (software rewrite mode is set). Software can be changed using the RS - 232C interface.

Default Settings

To Default, unplug (Power OFF), Set DIP SWITCH #5 to ON, Plug power in (power ON), then flip dip-switch 5 to OFF. Will then set to: