Some answers below.
John
On 7/3/20 10:54 AM, w8ycm--- via time-nuts wrote:
New guy here needs help using the TAPT TICC and Timelab software
The TICC documentation, I am sure, is sufficient to those in the community,
but to someone who has only lurked around the edges, there are a few
questions I have. I suspect some are obvious, and some others of no
consequence, so here goes:
M Measurement Mode T default T
S clock Speed (MHz) 10.000000 default 10
C Coarse Clock Rate (us) 100.000000 default 100
P calibration Periods 20 default 20
T Timeout 0x05 default 0x05
Y sync: master / slave M default M
E trigger Edge R R default R
D time Dilation 2500 2500 default 2500
F Fixed Time2 0 0 default 0
G fudge0 0 0 default 0
(1) In M (Measurement mode), what is the use for the “ L TimeLab
interval mode “? Should it only be used with Timelab? If “Yes” skip and b:
"TimeLab" mode is a special configuration for doing three-corner hat
measurements. Don't use it unless you know what those are, and why they
may not work. :-)
a. In M (Measurement mode), the functions of the T/P/I,
modes are reasonably obvious,
but with ones should be used with Timelab to compute Allan Deviation.
TimeLab works in "normal" fashion with either time interval, or one or
two channel timestamp, data. Of course, you need to configure TimeLab
to match what's coming out of the TICC.
b. Are any of the Measurement modes of particular use in
other Timelab functions?
You could probably kludge the period data mode to work with TimeLab, but
that one would not normally be used for a typical stability analysis.
It shows the period (inverse of frequency) of the input channel.
****
All of the following questions could be answered with, "Leave them alone
unless you're doing hardware or software development" but I'll try to
provide some info. To make much sense of it, you would need to study
the TICC schematics and source code, and also spend some quality time
with the TDC7200 chip data sheet.
(2) In M (Measurement mode), what does one do with “ D Debug
mode”?
Nothing, unless you're working on the code. That mode outputs the raw
data values used within the system and is for testing purposes.
(3) What is the rational for selecting a particular “Coarse Clock
Rate” value?
The Coarse Clock needs to match the hardware configuration. Unless
you're changing the TICC hardware (or the PIC divider chip), don't
change this.
(4) What is the rational for selecting a particular “calibration
Periods” value?
Trade-off of measurement speed vs. calibration accuracy.
(5) What is the rational for selecting a particular “Timeout” value?
Trade-off of measurement speed vs. proper operation.
(6) What is the rational for selecting a particular “time Dilation”
value?
There's a small non-linearity in the TDC7200 chip output and this value
compensates for that. It's determined experimentally and seems to be
about the same in all units.
(7) What do the “Fixed Time” options do, and why?
It's an experimental configuration option that in theory could provide
slightly less jitter in the results. We haven't proven whether or not
it actually does.
(8) What do the “Fudge” options do, and why?
These allow you to "trim" the results to account for slightly differing
cable lengths or path delays. By experimental adjustment, you can use
there to match the channel A and channel B results to compensate for
these variations. It's not normally necessary to mess with them.
John
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