TrueTime 151-602 - 3-229 SERIAL FUNCTION F29 - FREQUENCY MEASUREMENT INPUT (OPTION)

X
X
L
L
D
D
C
C
M
M
A
A
N
N
.
.
d
d
o
o
c
c
3
3
-
-
5
5
3
3
R
R
E
E
V
V
E
E
where:
<NSEC> = 9-digit subsecond string
<CR> = carriage return character
<LF> = line feed character
The interval is expressed as a decimal fraction of seconds. The port will continue to update and output
an interval measurement once each second until the Serial Port receives a CTRL-C character.
Sample entry: F28 ti<CR>
Response: .123456700<CR><LF>
Meaning: The interval is 0.123456700 seconds
If the mode was ET, the port will respond with a string or strings of the form:
<DAY>:<HOUR>:<MIN>:<SEC>.<NSEC><CR><LF>
where:
<DAY> = 3-digit day of year
: = ASCII colon character
<HOUR> = 2-digit hours
<MIN> = 2-digit minutes
<SEC> = 2-digit seconds
<NSEC> = 9-digit subsecond string
<CR> = carriage return character
<LF> = line feed character
Up to ten events each second may be timed if the events are continuous. A burst of 100 events within
1.0 s may be recorded. The resolution is 30 ns. Send a CTRL-C to exit this mode.
Sample entry: F28 ET<CR>
Response: 111:22:33:44.123456700<CR><LF>
3-229 SERIAL FUNCTION F29 - FREQUENCY MEASUREMENT INPUT (OPTION)
Refer to section 1-42 for information concerning the Frequency Measurement Input. Use Serial
Function F29 to set the measurement mode, input frequency and measurement interval parameters
and to view the current settings and the measurement data.
This function provides the capability to measure the frequency of an externally applied 1, 5, or 10 MHz
signal very accurately with respect to the disciplined XL-DC oscillator. The resolution of the
measurements is 6 parts in 10
-11
divided by the Measurement Interval. The range of fractional
frequency offset from the nominal input frequency which may be measured is ±500 PPM. The
Measurement Interval may be specified in integer seconds over the range of 1 to 100,000 seconds.