Operating Manual

IRS31Pro-UMB Operating Manual V10 / 01.2020
G. Lufft Mess- und Regeltechnik GmbH 48
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
01h 10h 01h 90h 01h F0h 04h 02h 23h 10h 65h 00h 03h 85h DCh 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 90h 0Ah 02h 23h 10h 00h 65h 00h 16h
<value> ETX <cs> EOT
15 16 17 18 19 20 21 22
ECh F2h C4h 41h 03h 24h 51h 04h
Interpretation of the response:
<status> = 00h device o.k. (≠ 00h signifies error code; see chapter 18.3.5)
<typ> = Data type of the following value; 16h = float (4 bytes, IEEE format)
<value> = 41C4F2ECh corresponds to a float value of 2.46186E+0001 = 24.6
The road surface temperature is therefore 24.6°C.
Correct data transmission can be checked with the aid of the check sum (5124h).
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.
18.3.5 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
2Bh (43d) Error in measurement
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 unable to carry out valid measurements due to ambient conditions
18.3.6 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 the UMB protocol.
18.3.7 Recording of a Communication with the UMB Config Tool
The UMB Config Tool uses the command ‘Online data request multiple channels’ (2Fh) for the data
request.