Lufft MARWIS, User Manual

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Operating Manual V 3.3 / 9 Dec 2019 MARWIS-UMB
20.3.5.2 Transmission format
The first data byte contains a status byte (see chapter 20.3.8) which indicates if a valid value is
available. If the status is not OK no more data will follow.
If the status is OK (0x00h) it will be followed by the second data byte which specifies the data
type in which the value is released (see chapter 20.3.9).
Depending on the data type 1 – 4 byte with measured values will follow from the third data byte
on.
Examples:
11 Bit
Identifier
(hex) IDE 18 Bit
Identifier
(hex)
RTR Data
Length
Code Data byte (hex) Description
1
Status
2
Typ
3 - 6
Messwert
0x000 1 0x00064 0 1 0x54 - Road temperature:
no valid value
0x000 1 0x00258 0 6 0x00 0x16 0x00 0x00
0x00 0x00
Water film heigh is 0
0x000 1 0x00384 0 3 0x00 0x10 0x01 Road state: 1 (humid)
20.3.6 Remote Query
Marwis supports remote value queries. Following the CAN specifications the CAN ID
corresponds to the CAN ID which is used for transmitting the corresponding value with
additionally set RTR bit.
The required value is transferred instantly one time only.
Examples:
Value Value number
(dez. / hex) 11 Bit
Identifier
(hex) IDE 18 Bit
Identifier
(hex) RTR CAN-ID
(extended)
Road temperature in °C
100d = 0x0064h
0x000 1 0x00064 1 0x00000064
Water film height in µm 600d = 0x0258h 0x000 1 0x00258 1 0x00000258
Road state 900d = 0x0384h 0x000 1 0x00384 1 0x00000384
20.3.7 Configuration of a trigger
If a value is supposed to be transferred several times, a trigger can be configured which defines
under which circumstances the value is supposed to be sent. Every value can have a trigger of
its own.
In the default settings no values will be transferred.
20.3.7.1 CAN-ID
The configuration of every value trigger has its own CAN ID. The default settings correspond to
the CAN IDs of the value transfer with additionally set lowest value bit of the 11 bit identifier.
Chapter 20, Appendix 53