User's Manual

SYMEO Local Positioning Radar System
LPR-1DXi
Product Documentation
Protocol Description
Copyright © Symeo GmbH 2009
Page 29 of 33
6.1.3 CRC
The CRC-16-IBM with polynomial x
16
+x
15
+x
2
+1 is used for the CRC. The CRC is calculated
over all data fields (TYPE and DATA), but not for the START and END field.
The CRC-calculation is only applied to the original symbols. The appropriate calculation for
coding must applied before byte stuffing. If receiving the data from the LPR-B system the
byte stuffing must be reserved to get the original symbol. Then the CRC is updated with the
original symbol.
6.2 Data Types
6.2.1 Type 0x00 – Distance Data
Direction: LPR-1DXi → User
Content
Length
Value
Data type
START
1
0x7E
TYPE
1
0x00
Source
*
(LPR
address
6.3.1
)
2
0x####
see chapter 6.3.1
Destination
*
(LPR
address
6.3.1
)
2
0x####
see chapter 6.3.1
Antenna number
1
0x11
unsigned integer
Distance [mm]
4
0x#### ####
signed integer
Velocity [mm/s]
4
0x#### ####
signed integer
Level [dB]
1
0x##
signed integer
Error
6.3.3
1
0x##
unsigned integer
Status
6.3.2
1
0x0#
unsigned integer
CRC
2
0x####
END
1
0x7F
Total length without byte stuffing: 21 byte
*
) Measurements are always executed by a LPR-1DXi base station (station 1), this means, the base
station measures its distance towards a transponder unit (station 2). The source field always contains
the address of the LPR-1DXi base station (station 1). The destination field contains the address of the
measured transponder (station 2).
6.2.2 Example of Distance Data
7E 00 08 03 08 02 11 00 00 10 62 00 00 00 7A E6 00 00 AF C4 7F
Figure 31 - Protocol for a measurement of distance data
This protocol shows a simple example for 1D measurement. The Distance Data sends the
data to the user (i.e. to a PLC or to a PC/software).