Specifications

Model E8 Series Operation Manual
E8 Series A5 Manual 9 October 2008
Page 7 of 12
Microcontroller Interface
The microcontroller interface allows setup and debug of the digital phase lock loop which locks the
20MHz reference oscillator to the GPS receiver. The list of control codes is given in an appendix.
The only user adjustable parameter is the PLL bandwidth, which is accessed with command "UA".
The band width has been factory set to optimum for the E8-X (TCXO) and the E8-Y (OCXO). It is
only recommended that the user adjusts these values if he is able to measure Allen variance of the
10MHz output at averaging times between 1 and 1000 seconds.
"UA?" will return the current bandwidth (0 to 7, with 0 the narrowest bandwidth)
The second parameter (hex) is the elapsed running time in units of 2.33 hours.