Siemens 6ES7153-1AA03-0XB0 - Page 154

Functions
8.2 Time stamping the input signals with IM 153-2
ET 200M
154 Operating Instructions, 04/2022, EWA-4NEB7806006-09
Structure of a special message
A special message always comes from the IM 153-2 (slot 2). It is structured as follows:
Table 8- 7 Structure of a special message
Meaning Number of
bytes
Remarks
Slot number of the
IM 153-2
1
Always "2" in the case of a special message
Code of the special mes-
sage
1
01h
Start-up data (a)
02h
Time message frame failure: the following signal messages have,
among others, a precision that is less than 10 ms (b)
03h
not used
04h
Time difference between message frame and internal clock > 10 ms
(c)
(message always occurs as a message pair)
05h
STOP of the time stamping (b)
06h
Buffer overflow: the following signal messages are lost until the buff-
er is clear again (b)
07h
Changeover in the case of redundancy (a)
08h
Loss of information in the case of redundancy (b)
(internal error)
Property for special mes-
sage
1
01h
(a) BEGIN
00h
(a) END
01h
(b) INCOMING
00h
(b) OUTGOING
01h
(c)
internal time of the
IM 153-2 at the mo-
ment of synchroniza-
tion
00h
(c)
Synchronization time to which the
internal clock of the IM 153-2 is
set
From the message pair of the special message (c) it can be seen
whether the internal clock has been put back or forward and how
great the time difference was during at the synchronization.
Reserved
1
Unassigned
Time of the special mes-
sage
8 (2 DW)
Time stamp in ISP-format
(refer to table below for structure)
Structure of a time stamp in the ISP format
A time stamp in the ISP format is structured as follows:
Table 8- 8 Structure of a time stamp in the ISP format
Byte
Contents
range
0 … 3
Seconds as of 01.01.1900; 0:00:00,000 o´clock
in accordance with
01.01.1900 … 06.02.2036
4 … 7
Fractions of a second in multiples of 1/(2
32
) s
0 … < 1 s