Difference between revisions of "Protocol decoder:Dcf77"

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| output          = dcf77
| output          = dcf77
| probes          = DATA
| probes          = DATA
| optional_probes = PON
| optional_probes = —
| options        = —
| annotations    = Text, Warnings
}}
}}


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== Hardware ==
== Hardware ==
TODO.


=== DCF77 on the Pollin DCF1 module ===
=== DCF77 on the Pollin DCF1 module ===
Line 59: Line 55:
== Protocol ==
== Protocol ==


TODO: Detailed protocol description.
=== Time code interpretation (taken from Wikipedia) ===
 
The time is represented in binary-coded decimal (BCD). It represents civil time, including summer time adjustments. The time transmitted is the time of the ''following'' minute; e.g. during December 31 23:59, the transmitted time encodes January 1 00:00.
 
<small>
{|class=wikitable style="text-align:center"
|+
!rowspan=2| Bit ||colspan=2| Weight ||rowspan=2| Meaning
|rowspan=22|
!rowspan=2| Bit ||colspan=2| Weight ||rowspan=2| Meaning
|rowspan=22|
!rowspan=2| Bit ||colspan=2| Weight ||rowspan=2| Meaning
|-
! PM || AM || PM || AM || PM || AM
|-
|bgcolor=#ffccff| :00 ||bgcolor=#ffccff| 1 ||bgcolor=#ffccff| M ||bgcolor=#ffccff| Start of minute. Always 0.
|bgcolor=#ffccff| :20 ||colspan=2 bgcolor=#ffccff| S ||bgcolor=#ffccff| Start of encoded time. Always 1.
|bgcolor=#ccffcc| :40 ||colspan=2 bgcolor=#ccffcc| 10 ||rowspan=2 bgcolor=#ccffcc|Day of month (continued)
|-
| :01 ||bgcolor=#ffccff| 1 ||colspan=2 rowspan=14| Civil warning bits, provided by the<br>''Bundesamt für Bevölkerungsschutz<br>und Katastrophenwarnung'' (Federal Office<br>of Civil protection and Disaster Relief).<br>Also contains weather broadcasts.
|bgcolor=#ffffcc| :21 ||colspan=2 bgcolor=#ffffcc| 1 ||rowspan=7 bgcolor=#ffffcc| Minutes<br>00–59
|bgcolor=#ccffcc| :41 ||colspan=2 bgcolor=#ccffcc| 20
|-
| :02 ||bgcolor=#ffccff| 1
|bgcolor=#ffffcc| :22 ||colspan=2 bgcolor=#ffffcc| 2
|bgcolor=#ccffcc| :42 ||colspan=2 bgcolor=#ccffcc| 1 ||rowspan=3 bgcolor=#ccffcc| Day of week<br>Monday=1, Sunday=7
|-
| :03 ||bgcolor=#ffccff| 1
|bgcolor=#ffffcc| :23 ||colspan=2 bgcolor=#ffffcc| 4
|bgcolor=#ccffcc| :43 ||colspan=2 bgcolor=#ccffcc| 2
|-
| :04 ||bgcolor=#ffccff| 1
|bgcolor=#ffffcc| :24 ||colspan=2 bgcolor=#ffffcc| 8
|bgcolor=#ccffcc| :44 ||colspan=2 bgcolor=#ccffcc| 4
|-
| :05 ||bgcolor=#ffccff| 1
|bgcolor=#ffffcc| :25 ||colspan=2 bgcolor=#ffffcc| 10
|bgcolor=#ccffcc| :45 ||colspan=2 bgcolor=#ccffcc| 1 ||rowspan=5 bgcolor=#ccffcc| Month number<br>01–12
|-
| :06 ||bgcolor=#ffccff| 1
|bgcolor=#ffffcc| :26 ||colspan=2 bgcolor=#ffffcc| 20
|bgcolor=#ccffcc| :46 ||colspan=2 bgcolor=#ccffcc| 2
|-
| :07 ||bgcolor=#ffccff| 1
|bgcolor=#ffffcc| :27 ||colspan=2 bgcolor=#ffffcc| 40
|bgcolor=#ccffcc| :47 ||colspan=2 bgcolor=#ccffcc| 4
|-
| :08 ||bgcolor=#ffccff| 1
|bgcolor=#ffffcc| :28 ||colspan=2 bgcolor=#ffffcc| P1 ||bgcolor=#ffffcc| Even parity over minute bits 21–28.
|bgcolor=#ccffcc| :48 ||colspan=2 bgcolor=#ccffcc| 8
|-
| :09 ||bgcolor=#ffccff| 1
|bgcolor=#ffcccc| :29 ||colspan=2 bgcolor=#ffcccc| 1 ||rowspan=6 bgcolor=#ffcccc| Hours<br>0–23
|bgcolor=#ccffcc| :49 ||colspan=2 bgcolor=#ccffcc| 10
|-
| :10 ||bgcolor=#ffccff| 0
|bgcolor=#ffcccc| :30 ||colspan=2 bgcolor=#ffcccc| 2
|bgcolor=#ccffcc| :50 ||colspan=2 bgcolor=#ccffcc| 1 ||rowspan=8 bgcolor=#ccffcc| Year within century<br>00–99
|-
| :11 ||bgcolor=#ffccff| 0
|bgcolor=#ffcccc| :31 ||colspan=2 bgcolor=#ffcccc| 4
|bgcolor=#ccffcc| :51 ||colspan=2 bgcolor=#ccffcc| 2
|-
| :12 ||bgcolor=#ffccff| 0
|bgcolor=#ffcccc| :32 ||colspan=2 bgcolor=#ffcccc| 8
|bgcolor=#ccffcc| :52 ||colspan=2 bgcolor=#ccffcc| 4
|-
| :13 ||bgcolor=#ffccff| 0
|bgcolor=#ffcccc| :33 ||colspan=2 bgcolor=#ffcccc| 10
|bgcolor=#ccffcc| :53 ||colspan=2 bgcolor=#ccffcc| 8
|-
| :14 ||bgcolor=#ffccff| 0
|bgcolor=#ffcccc| :34 ||colspan=2 bgcolor=#ffcccc| 20
|bgcolor=#ccffcc| :54 ||colspan=2 bgcolor=#ccffcc| 10
|-
|bgcolor=#ccffff| :15 ||colspan=2 bgcolor=#ccffff| R ||bgcolor=#ccffff| Call bit: abnormal transmitter operation.<br>Previously: backup antenna in use.
|bgcolor=#ffcccc| :35 ||colspan=2 bgcolor=#ffcccc| P2 ||bgcolor=#ffcccc| Even parity over hour bits 29–35.
|bgcolor=#ccffcc| :55 ||colspan=2 bgcolor=#ccffcc| 20
|-
|bgcolor=#ccffff| :16 ||colspan=2 bgcolor=#ccffff| A1 ||bgcolor=#ccffff| Summer time announcement.<br>Set during hour before change.
|bgcolor=#ccffcc| :36 ||colspan=2 bgcolor=#ccffcc| 1 ||rowspan=4 bgcolor=#ccffcc| Day of month.<br>01–31
|bgcolor=#ccffcc| :56 ||colspan=2 bgcolor=#ccffcc| 40
|-
|bgcolor=#ccffff| :17 ||colspan=2 bgcolor=#ccffff| Z1 ||bgcolor=#ccffff| Set to 1 when CEST is in effect.
|bgcolor=#ccffcc| :37 ||colspan=2 bgcolor=#ccffcc| 2
|bgcolor=#ccffcc| :57 ||colspan=2 bgcolor=#ccffcc| 80
|-
|bgcolor=#ccffff| :18 ||colspan=2 bgcolor=#ccffff| Z2 ||bgcolor=#ccffff| Set to 1 when CET is in effect.
|bgcolor=#ccffcc| :38 ||colspan=2 bgcolor=#ccffcc| 4
|bgcolor=#ccffcc| :58 ||colspan=2 bgcolor=#ccffcc| P3 ||bgcolor=#ccffcc| Even parity over date bits 36–58.
|-
|bgcolor=#ccffff| :19 ||colspan=2 bgcolor=#ccffff| A2 ||bgcolor=#ccffff| Leap second announcement.<br>Set during hour before leap second.
|bgcolor=#ccffcc| :39 ||colspan=2 bgcolor=#ccffcc| 8
|bgcolor=#ff88ff| :59  ||bgcolor=#ffccff| 0 ||colspan=2 bgcolor=#ff88ff| Minute mark: no amplitude modulation.
|}
</small>


== Resources ==
== Resources ==


TODO.
* [https://en.wikipedia.org/wiki/DCF77 Wikipedia: DCF77]
* [http://www.ptb.de/cms/en/fachabteilungen/abt4/fb-44/ag-442/dissemination-of-legal-time/dcf77.html TCP: DCF77] (German)


[[Category:Protocol decoder]]
[[Category:Protocol decoder]]

Revision as of 19:16, 1 February 2014

dcf77
Pollin dcf1 dcf77 module device top.jpg
Name DCF77 time protocol
Description European longwave time signal (77.5kHz carrier signal)
Status supported
License GPLv2+
Source code decoders/dcf77
Input logic
Output dcf77
Probes DATA
Optional probes —

The dcf77 protocol decoder supports the DCF77 european longwave time signal (77.5kHz carrier signal).

Hardware

DCF77 on the Pollin DCF1 module

The dcf77/pollin_dcf1_module directory in sigrok-dumps contains a set of example captures of a DCF77 signal. The hardware used for receiving the signal is a Pollin DCF1 module (3.3V supply). The Pollin order number for the module is 810 054.

The dumps were made January 9, 2012 in the evening/night. Only the dcf77_480s_pon_interrupted.sr dump was made January 10, 2012 in the evening.

The logic analyzer used was a Saleae Logic (at 1MHz).

Probe setup:

Probe DCF1 module
1 (black) PON
2 (brown) DATA

Photos:

  • Pollin dcf1 dcf77 module device top.jpg
  • Pollin dcf1 dcf77 module device bottom.jpg
  • Pollin dcf1 dcf77 module probe setup.jpg
  • Pollin dcf1 dcf77 module probing1.jpg
  • Pollin dcf1 dcf77 module probing2.jpg
  • Pollin dcf1 dcf77 module probing3.jpg

Protocol

Time code interpretation (taken from Wikipedia)

The time is represented in binary-coded decimal (BCD). It represents civil time, including summer time adjustments. The time transmitted is the time of the following minute; e.g. during December 31 23:59, the transmitted time encodes January 1 00:00.

Bit Weight Meaning Bit Weight Meaning Bit Weight Meaning
PM AM PM AM PM AM
:00 1 M Start of minute. Always 0. :20 S Start of encoded time. Always 1. :40 10 Day of month (continued)
:01 1 Civil warning bits, provided by the
Bundesamt für Bevölkerungsschutz
und Katastrophenwarnung (Federal Office
of Civil protection and Disaster Relief).
Also contains weather broadcasts. 		:21 1 Minutes
00–59 		:41 20
:02 1 :22 2 :42 1 Day of week
Monday=1, Sunday=7
:03 1 :23 4 :43 2
:04 1 :24 8 :44 4
:05 1 :25 10 :45 1 Month number
01–12
:06 1 :26 20 :46 2
:07 1 :27 40 :47 4
:08 1 :28 P1 Even parity over minute bits 21–28. :48 8
:09 1 :29 1 Hours
0–23 		:49 10
:10 0 :30 2 :50 1 Year within century
00–99
:11 0 :31 4 :51 2
:12 0 :32 8 :52 4
:13 0 :33 10 :53 8
:14 0 :34 20 :54 10
:15 R Call bit: abnormal transmitter operation.
Previously: backup antenna in use. 		:35 P2 Even parity over hour bits 29–35. :55 20
:16 A1 Summer time announcement.
Set during hour before change. 		:36 1 Day of month.
01–31 		:56 40
:17 Z1 Set to 1 when CEST is in effect. :37 2 :57 80
:18 Z2 Set to 1 when CET is in effect. :38 4 :58 P3 Even parity over date bits 36–58.
:19 A2 Leap second announcement.
Set during hour before leap second. 		:39 8 :59 0 Minute mark: no amplitude modulation.

Resources

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