Specifications

Model E8 Series Operation Manual
E8 Series A5 Manual 9 October 2008
Page 11 of 12
Appendix B
RS232 control codes
(all values following command or returned from the microcontroller are hexadecimal)
* = backed up in EEPROM
UA User adjust
UA? Returns user parameters aa bbbb
* aa is bandwidth control: bits set: bit0, 1, 2: bandwidth (0 to 7)
* bbbb is clock registers 3 and 4 (elapsed time)
UABaa Write new bandwidth control byte
OS Overall Status
OS? Returns overall status bytes: aa bb cccc
aa is test status byte:
Bits set: bit0, 1, 2: bits 0 to 2 DAC output select
bit3: no integrator update
bit4: no proportional term
bit5: Inhibit holdover mode
bit6: NU
bit7: inhibit state control
Bits 2, 1, 0: 000 no test output, fine tune DAC used for tuning
001 sub sampled I
010 sub sampled Q
011 PLL Integrator upper 16 bits
100 Phase result
101 I sample (filtered)
110 Q sample (filtered)
111 references CH6 (filtered)
bb is lock status byte:
Bits set bit0 to 2: State control, states 0 to 7
bit3: set to normalise tuning DACs (cleared automatically)
bit4: NU
bit5: Loop locked
bit6: narrow range phase detector in use
bit7: set to inhibit auto load of PLL gain parameters
cccc is PLL control:
Bits set bit0, 1, 2, 3 subsample rate
bit4, 5, 6, 7 exp filter order
bit8, 9, 10, 11 integrator gain
bit12, 13, 14, 15 proportional gain
OSTaa Write new test status byte
OSLbb Write new lock status byte
OSGcccc Write new PLL control