Operating Manual CHM 15k
R13 / 07-2019
Communication via RS485 & Ethernet
35
Byte
Value
1
Description
83-90
********
System status: 32 Bit status code; see section 8.5
91
<SPACE>
20 HEX
92, 93
**
Checksum (two's complement of the sum of bytes 0 to 96
expressed in hex code, excluding bytes 92 and 93)
94
<CR>
0D HEX
95
<LF>
0A HEX
96
<EOT>
04 HEX
Table 8
Standard data telegram format, * can be any desired character.
Up to three cloud heights are stated in the standard telegram. If less than three cloud heights are
detected, the message
NODET
appears in the remaining fields. If cloud depths are not determined, the
message
NODT
appears in the corresponding fields.
A
NODET
value is also entered in the fields if the algorithm is unable to calculate the following values:
•
Visibility
•
Maximum detection range
If the values cannot be determined due to a device error, these fields are filled with a minus sign "-" or
slash "/". Detailed information on the type of device error can be found in the status codes (see
Correction of the measured cloud height
The cloud height is usually measured from the bottom of the device. If the parameter
"altitude(m)" is set to a value other than zero and "usealtitude" is set to 1, the cloud height
is corrected by this factor. Instead of the relative height axis an absolute altitude axis is
used.
In the NetCDF data, the variable CHO indicates whether the parameter "usealtitude" is
set.
8.3.4 Extended data telegram
The extended data telegram consists of 240 Bytes, when the default number for layer size of 3 is selected,
see Table 9. The number of cloud layers is specified in the parameter
“Layer (NoL)”, see Table 4.
In the extended data telegram a semicolon (3B HEX) is used as the separator instead of the space (20
HEX).
Byte
Value
1
Description
0
<STX>
20 HEX
1
X
2
1
3, 4
TA
5
;
3B HEX
6
8
7
;
3B HEX
8-10
***
Output interval [s]
11
;
3B HEX
12-19
** ** **
Date (dd.mm.yy)
20
;
3B HEX
21-28
**:**:**
Time (hh:mm:ss)
29
;
3B HEX
30
*
Number of layers
31
;
3B HEX
Summary of Contents for CHM 15k
Page 1: ...General Information 1 Titelseite...
Page 73: ...Index of Tables 73...
