Operating Manual Compact Weather Station
G. Lufft Mess- und Regeltechnik GmbH, Fellbach, Germany 51
18.3.3 Examples for Creating Addresses
If, for example, you want to address WS400-UMB with the device ID 001, this takes place as
follows:
The class ID for the compact weather station is 7d = 7h;
the device ID is e.g. 001d = 001h
Putting the class and device IDs together gives the address 7001h (28673d).
18.3.4 Example of a Binary Protocol Request
If, for example, a compact weather station with the device ID 001 is to be polled from a PC
for the current temperature, this takes place as follows:
Sensor:
The class ID for the compact weather stationis 7 = 7h;
the device ID is 001 = 001h
Putting the class and device IDs together gives a target address of 7001h.
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 num
ber is in <payload
>; as can be seen from
the channel list (pa
ge 47), the
current temperature in °C in the channel is 100d = 0064h.
The calculated CRC is D961h.
The request to the device:
The response from the device:
Interpretation of the response:
<status> = 00h device o.k. (≠ 00h signifies error code; see page 52)
<typ> = Data type of the following value; 16h = float (4 bytes, IEEE format)
<value> = 41B40000h as a float value corresponds to 22.5
The temperature is therefore 22.5°C.
The correct data transmission can be checked with the aid of the check sum (22C6h).
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 LowByte and then the HighByte.
To Next Page
Loading...
Need help?
General
