Variables


The Variables screen provides a list of 36 operating parameters. The parameters are described in the table below.

 

No.

Name

Description

Example

1

loop order

loop design, first or second order; default = 2

2

2

cesium servo mode

R+Z = oscillators locks to ramsey peak, c-field locks to zeeman peak

R+T = oscillator locks to ramsey peak, c-field is constant

R+Z

3

4-state indicator

00 = LOCK (no faults)

01 = INITIALIZATION (CRITICAL for TL1)

10 = MINOR ALARM

11 = CRITICAL ALARM

00

4 - 8

5-place fault buffer

refer to table of faults, Table 2-4

00,00,00,00,00

9

C-field adjust

parts in 10-13 frequency adjustment using the cesium beam tube’s C-field

+000

10

frequency adjust

parts in 10-15 frequency adjustment using the digital synthesizer

+001200

11

+25 V supply

voltage (V)

+25.3

12

loop time constant

1 to 999, in tenths of seconds

10.1

13

ramsey error

Represents the magnitude of the fine error signal on the main (ramsey) peak; <160 nominal.

+013

14

Rabi-ramsey error

Represents the magnitude of the coarse error signal on the main (Rabi) pedestal

+0012

15

zeeman error

Represents the magnitude of the fine error signal on the side (zeeman) peak; <160 nominal.

+008

16

Rabi-zeeman error

Represents the magnitude of the coarse error signal on the side (Rabi) pedestal

+0036

17

ocxo control

Represents the control voltage controlling the ovenized quartz crystal oscillator; ±500 at start of life, ±4900 at end-of-life.

-1318

18

Ramsey peak

Represents the magnitude of the main (Ramsey) peak;
(2500 ± 200 nominal)

2495

19

C-field control

Represents the magnitude of the C-field control voltage
(0 ± 400 nominal)

+0080

20

zeeman peak

Represents the magnitude of the first side (zeeman) peak; (Ramsey level - 200 ±200 nominal)

1677

21

Ramsey level offset

Represents the magnitude of the offset voltage added to the Ramsey response to center it within the range of the A/D converter; 60 to 200 nominal, proportional to loop gain factor.

2

22

software (numerical) gain

gain applied to the beam signal, 1 to 5; interacts with the hardware (DAC) gain

R+Z

23

Ramsey confidence

confirms central Ramsey symmetry by checking that the difference between adjacent valleys is small, <10 nominal.

00

24

microwave power

represents the magnitude of the microwave power applied to the cesium beam tube

-0408

25

+5 V power supply

voltage (V)

+5.17

26

internal temperature

°C

+35.5

27

+15 V power supply

voltage (V)

+15.4

28

-15 V power supply

voltage (V)

-15.4

29

crystal oven state

F = cold, C = warm

C

30

cesium oven supply

voltage (V): 12 during warm-up, approximately 5 quiescent

04.5

31

mass spec supply

voltage (V) of the ionizer filament with respect to ground

15.5

32

ionizer supply

voltage (V) across the ionizer filament

1.66

33

C-field supply

current (mA) through the C-field winding

17.9

34

EM HV supply

voltage (V) applied to the primary of the electron multiplier high voltage supply (-2000 V)

10.6

35

IP HV supply

current (mA) being supplied by the ion pump high voltage supply (+3500 V)

025

36

standard deviation

a measure of the frequency stability of the unit - 90 to 125 for a 12-year tube

+107