4.1.4.5 TPC FDM String
The TPC string is a sequence of 29 ASCII characters containing the REF time (with day-of-the-year), the time
deviation TD and the frequency deviation FD. The string starts with the SOH character (start-of-header, ASCII
code 01h) on time with the beginning of every new REF time second and ends with the characters Carriage-
Return (ASCII code 0Dh) and Line-Feed (ASCII code 0Ah). The letters displayed in italics are replaced by the
calculated values whereas the other characters are part of the string:
<SOH>288:10:11:29 -00.03F+50.01<CR><LF>
The meaning of the several values is described below:
288:10:11:29
the reference time from the upstream radio clock,
(day of year:hours:minutes:seconds)
’ ’ oder ’?’
if reference time is synchron then ’ ’ otherwise ’?’
-00.03
the mains frequency deviation from the setpoint, resolution 1mHz
F+50.01
The power line frequency, 10mHz resolution
4.1.4.6 Computime Extended FDM String
The extended Computime string is a sequence of 42 ASCII characters containing the REF time (with date and
day-of-the-week), the time deviation TD and the frequency F. The string is send out at the beginning of every
new REF time second and ends with the characters Carriage-Return (Hex code 0Dh) and Line-Feed (Hex code
0Ah). The letters displayed in italics are replaced by the calculated values whereas the other characters are
part of the string:
T:
10:03:09:02:15:03:30
D:
+000.378F:49.984
<CR><LF>
The meaning of the several values is described below:
T:
10:03:09:02
The date of the reference time from the preconnected clock,
(year:month:day:day-of-the-week / Monday = 01, Sunday = 07)
15:03:30
The reference time from the preconnected clock,
(hours:minutes:seconds)
D:
+000.378
The time deviation between REF time and PL time,
with sign character (+/-), resolution: 1ms,
maximum: +-99.999s (the first digit is always 0!)
F:
49.984
The measured power line frequency with a resolution of 1mHz
20
Date: 4th November 2020
IMS-FDM Setup Guide
