Users Manual

Operating Manual Smart Weather Sensor
G. Lufft Mess- und Regeltechnik GmbH, Fellbach, Germany 83
19.3.5 Status and Error Codes in Binary Protocol
If a measurement request delivers the <status> 00h, the sensor is working correctly. You can
find a complete list of additional codes in the description of the UMB protocol.
Extract from list:
<status>
Description
00h (0d)
Command successful; no error; all o.k.
10h (16d)
Unknown command; not supported by this device
11h (17d)
Invalid parameter
24h (36d)
Invalid channel
28h (40d)
Device not ready; e.g. initialization / calibration running
50h (80d)
Measurement variable (+offset) is outside the set display range
51h (81d)
52h (82d)
Measurement value (physical) is outside the measuring range (e.g. ADC over range)
53h (83d)
54h (84d)
Error in measurement data or no valid data available
55h ( 85d)
Device / sensor is unable to execute valid measurement due to ambient conditions
19.3.6 CRC Calculation
CRC is calculated according to the following rules:
Norm: CRC-CCITT
Polynomial: 1021h = x
16
+ x
12
+ x
5
+ 1 (LSB first mode)
Start value: FFFFh
You can find further information in the description of a CRC calculation in UMB Protocol.
19.3.7 Data Request in Power Saving Mode 2
When in power saving mode2 the processor of the Smart Weather Sensor will be usually in
sleep state. For the acquisition of measurement data a certain command sequence and a
certain timing is required:
• „Wake Up“ bei sending a <Break>, any character or any telegram (a telegram will
not be properly detected and get no response, because the UART is just starting)
• 1000msec pause for the processor start up
• Activation of the measurement cycle by (any) valid telegram addressed to this
device
• 2000msec pause for the execution of the measurement sequence
• Request of the measurement results
Example of a Request Sequence:
Command Data Request (0x23), Channel 100
No response
Wait 1 sec
Command Data Request (0x23), Channel 100
Discard data
Wait 2 sec
CommandMultiData Request (0x2F), Ch. 100, 200, 300, 620, 605, 700
Store data