Gotting HG G-7335 ZB Series, Руководство пользователя

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Device Description HG G-7335xZB | English, Revision 06 | Date: 30.04.2020
31
CAN Interface (HG G-73350) – Chapter 8
Directly after the MSB the 8-Bit representation of the deviation value (marked green
in the below tables) does follow, while the remaining Bits of lower value are filled
with 0.
The internal deviation value in fact is a signed 9-bit number which has been shifted
by 7 digits to the left, which equals a multiplication by 128 (2^7).
The deviation value ranges between -32640 (=-255 x 128) and 32640 (255 x 128).
It is changing by 128 with each millimeter of change in the real deviation from the
guide wire. To obtain a millimeter value from the internal distance value you have to
divide this 16 bit number by 128.
Note
In case of a loss of wire a value of 256 mm will be returned which equals an internal
deviation value of -32768 (-256 x 128).
The millimeter value is generally indicated via the RS232 interface, while the internal
value is returned by the CAN bus from the interpreter. The values sent by CAN bus
have to be divided by 128 to obtain the millimeter values. The table below shows
some example values.
Table 16
CAN: Calculation of negative deviation values (example: maximum)
MSB LSB
1 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0
-255 x 128
= -32640
Table 17
CAN: Calculation of positive deviation values (example: maximum)
MSB LSB
0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0
255 x 128
= 32640
Table 18
CAN: Deviation value output for loss of wire
MSB LSB
1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
-256 x 128
= -32768
Table 19
CAN: Example values for the deviation value output
Internal Value
Deviation in mm
decimal binary hexadecimal
-25600 1001 1100 0000 0000 9C00 -200
-10240 1101 1000 0000 0000 D800 -80
2560 0000 1010 0000 0000 0A00 20
15360 0011 1100 0000 0000 3C00 120