SICK HIPERFACE DSL - Page 48

Bit 7 Bit 0
Bit 39-0 Safe position, byte 4/3/2/1/0:
Position value transmitted through Safe Channel 1 (length: 40 bits), absolute value.
6.3.16 Position checksum
The POSCRC registers for the position checksum contain the CRC checksum of the safe
position VPOS (see chapter 6.3.15) and the SUMMARY status summary (see
chapter 6.3.14).
The CRC is checked in the DSL Master IP Core. These registers can be checked with an
external cross check by the drive application.
The CRC is generated with the following CRC parameters:
Table 23: POSCRC parameters
Parameter Value
CRC sequence 16 Bit
CRC polynomial C86Ch (x
16
+ x
15
+ x
12
+ x
7
+ x
6
+ x
4
+ x
3
+ 1)
Normal representation: 90D9h
Starting value 0000h
Closing XOR value 00FFh
Reverse data bytes No
Reverse CRC before closing XOR No
The sequence of the bytes to calculate the CRC is shown in the following figure:
SAFE_SUM VPOS[39:32] VPOS[31:24] VPOS[23:16] VPOS[15:8] VPOS[7:0]
Figure 16: Sequence of the bytes to calculate the CRC
Register 1Eh:
CRC of the safe position, byte 1
R-0 R-0 R-0 R-0 R-0 R-0 R-0 R-0
CRC of the safe position, byte 1
Bit 15 Bit 8
Register 1Fh: CRC of the safe position, byte 0
R-0 R-0 R-0 R-0 R-0 R-0 R-0 R-0
CRC of the safe position, byte 0
Bit 7 Bit 0
Bit 15-0 CRC of the safe position:
16 bit CRC checksum (CRC 16) of the safe position and status summary in Safe Chan‐
nel 1.
6.3.17 Parameters Channel buffer
The eight PC_BUFFER registers of the Parameters Channel buffer contain the answer to
the last "long message" request or the data for a "long message" write operation.
NOTE
Access to these registers may only take place if the "long message" channel is free
(FREL in the EVENT_L register).
6 REGISTER MAP
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T E C H N I C A L I N F O R M A T I O N | HIPERFACE DSL
®
8017595/ZTW6/2018-01-15 | SICK
Subject to change without notice