Lufft V200A-UMB User Manual

Operating Manual V25/09.2019 Ventus / Ventus-X / V200A
Chapter 20 Appendix 41
Sensor:
The class ID for the Ventus is 8 = 8h;
the device ID is 001 = 01h
Putting the class and device IDs together gives a target address of 8001h.
PC:
The class ID for the PC (master unit) is 15 = Fh;
the PC ID is e.g. 001d = 01h
Putting the class and device IDs together gives a sender address of F001h.
The length <len> for the online data request command is 4d = 04h;
the command for the online data request is 23h;
the version number of the command is 1.0 = 10h.
The channel number is in <payload>; as can be seen from the channel list (page 38), the
current temperature in °C in the channel is 100d = 0064h.
The calculated CRC is 540Bh.
The request to the device:
SOH
<ver>
<to>
<from>
<len>
STX
<cmd>
<verc>
<channel>
ETX
<cs>
EOT
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
01h
10h
01h
80h
01h
F0h
04h
02h
23h
10h
64h
00h
03h
0Bh
54h
04h
The response from the device:
SOH
<ver>
<to>
<from>
<len>
STX
<cmd>
<verc>
<status>
<channel>
<typ>
1
2
3
4
5
6
7
8
9
10
11
12
13
14
01h
10h
01h
F0h
01h
80h
0Ah
02h
23h
10h
00h
64h
00h
16h
<value>
ETX
<cs>
EOT
15
16
17
18
19
20
21
22
00h
00h
B4h
41h
03h
1Fh
94h
04h
Interpretation of the response:
<status> = 00h device o.k. (≠ 00h signifies error code; see page 42)
<typ> = Data type of the following value; 16h = float (4 bytes, IEEE format)
<value> = 41B40000h corresponds to a float value of 22.5
The temperature is therefore 22.5°C.
The correct data transmission can be checked with the aid of the check sum (941Fh).
Note: Little Endian (Intel, low byte first) applies when transmitting word and float variables of
addresses or the CRC, for example. This means first the low byte and then the high byte.

Lufft V200A-UMB Specifications

General

Brand	Lufft
Model	V200A-UMB
Category	Accessories
Language	English