COM0
/
COM1
S
ERIAL
I
NTERFACES
System 6844(RC) - V03.00
119 / 157
hopf
Elektronik GmbH
Nottebohmstr. 41
• D-58511 Lüdenscheid • Tel.: +49 (0)2351 9386-86 • Fax: +49 (0)2351 9386-93 • Internet: http://www.hopf.com • E-Mail: [email protected]
6.3.14.2 Structure
Character No.
Meaning
Hex-Value
1
Start flag
$68
2
Length of Information
$0F
3
Repeated length of Information
$0F
4
Start flag
$68
5
Control field
$44
6
Station address
$FF
7
Frame Type identification
$06
8
Variable structure identifier
$81
9
Cause of transmission
$08
10
Common address of ASDU
$FF
11
Function type
$FF
12
Information number
$00
13
Milliseconds (Low octet)
$0000-EA5F
14
Milliseconds (High octet)
15
Minutes (0..59) + MSB = Invalid Flag
$00-3B, $80-BB
16
Hours (0..23) + MSB = SU Summer time Flag
$00-17, $80-97
17
Days (1..31)
$01-1B
18
Months (1..12)
$01-0C
19
Years (00..99)
$00-63
20
Checksum (sum of fields 5 to 19 mod 256)
$00-FF
21
End flag
$16
MSB of minute:
1 = clock is not synchronous (time invalid or quartz)
0 = clock is synchronous
MSB of hour:
1 = daylight saving time
0 = standard time
The seconds are displayed in the value of the milliseconds.
Thus the millisecond value runs from 0 .. 59999 decimal or from 0000 .. EA5F hexadecimal.
(If output is set to the minute change this value is always 0)
The checksum is the sum of byte 5 to 19 Modulo 256.
6.3.14.3 Example
The length of the data string is fixed to 21 characters. All characters including special char-
acters are allowed. Only binaurally values are transmitted.
The transmitted values are given out hexadecimal:
<68><0f><0f><68><44><ff><06><81><08><ff><ff><00><00><00><05><08><11><87><09><fe><16>
Time is 08:05:00.000 at 17
th
July 2009
daylight saving time
The clock is synchronous.
