Revised May 1, 2019
Revision 25 of DOCU225, © Copyright
Page 7 of 44
2 Understanding Pason WITS
2.1 Setting Up
Setting up and using WITS with a Pason EDR involves these general steps:
1. Physically connecting third-party hardware to the Pason system
2. Establishing WITS communication between the third-party device and the EDR,
often called handshaking
3. Setting up the EDR for WITS communication
4. Setting up the third-party device for WITS communication
The second step, establishing WITS communication, is typically where most problems
occur. To avoid WITS-related problems, consider the information below about WITS in a
Pason system.
2.2 Duplex Communication
Pason recommends full duplex communication when using WITS. With full duplex
communication, data can travel in two directions simultaneously. This is different than
half duplex communication, which allows data to travel in one direction at a time, like
voices on walkie-talkie radios.
2.3 Handshaking
Establishing and maintaining WITS communication between connected WITS devices
and the EDR requires a handshaking procedure. For details about how to complete the
handshaking process, see
on page 14.
2.4 About WITS Levels and Packets
The Pason system uses WITS Level 0 for serial communications. In Send and Receive
mode, the EDR transmits a number of WITS Level 0 packets (1 packet in Half WITS
mode, approximately 8 packets in Full WITS mode) each time it receives a valid WITS
Level 0 packet.
2.5 What is the 1984PASON/EDR Header
Every WITS record the Pason EDR sends includes a 1984PASON/EDR header. This
does not exactly meet the WITS specification, which specifies that items from different
