Hi Paul,
it is many years ago what I used DOS util. I use only win. version. But what I know is that the default baudrate is 9600 N 8 1 and ASCII protocol. For communication use connector ST21. The service connector ST23 no longer supported (from firmware V1.4 onwards). See attached doc. page 13. I think that, if all switches on S1 are Off the CTL unit is in default mode and is valid what I wrote above(default baudrate is 9600 N 8 1 and ASCII protocol). The red LED is flashing (it indicating reading cycle). When you will put near transponder too the antenna and everything is O.K. the green LED must flash. With Reader Utility you can try connect. Select Operation Mode -> ASCII Mode. If all O.K. the reader will send his Type and Version. If you get this information you can continue. Now select Operation Mode -> Config Mode. After this Reader Utility can try reproach parameters from EEPROM. In this mode you can change all parameters. For example Baud rate, Com.Intreface,Com.Protocol and so on. All changes will show after writing and switching first contact DIPswitch S1.
JURS