Overview

The communication protocol used by Cryodrive Pad to communicate with single and two stage coolers via Cryodrive is published here to allow users to integrate an Oxford Cryosystems device into custom control systems. Please note that this information applies only to Cryodrives with serial numbers starting at R71-0600 / R76-0583.

The Cryodrive incorporates an RS232 interface allowing communication with a remote computer. The communications fall into two categories. 

• Cryodrive  issues 'status packets' at regular (1 second) intervals. The status packets are of a fixed length and format.
• The controller listens for 'command packets' sent by the remote computer. These are small, variable length packets sent by the remote computer to the controller.

Protocols

For a detailed description of the status packets click status packet protocol, for command packets click command packet protocol.

Wiring

Cryodrive is shipped with a suitable connecting wire, the details of which are illustrated here. 

Serial line settings

Cryodrive uses the following R232 settings: 9600 baud, no parity, 1 stop bit.