Beckhoff KL3356, Documentation

Page: 48 / 55

Access from the user program
KL3356 48 Version: 2.3.0
User scaling can be enabled in the feature register via bit R32.0 [ } 47] .
R35: nominal weight of the load cell
The nominal weight of the connected load cell is entered into register R35. The unit is 1 kg.
R36: nominal parameter of the load cell
The nominal parameter of the connected load cell is entered into register R36. The unit is 1 mV / V.
R37: Filter constant of the A/D converter, and configuration bits for the filter
The KL3356 possesses two low-pass filter stages:
• The first stage consists of a sinc
3
filter, and is always active.
• The second stage consists of a 22nd order FIR filter, which can be disabled
(FIR: finite impulse response, i.e. a non-recursive filter).
Bit 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Name Filter constants SF (SF.11 to SF.0) Zero Zero SkipFIR Fast
Key
Bit Name Description Default
R37.15 Filter constant SF
(SF.11 - SF.0)
The filter constant SF specifies the 3dB limit frequency of the sinc
3
filter. The value ranges from 150 to 2047.
The 3 dB limit frequency F
Limit
and the 64.5 dB stop frequency F
Stop
are calculated as follows:
35C
hex
(860
dec
)
...
R37.4
SkipFIR = 0 F
Limit
= 11981 / SF
F
Stop
= 43008 / SF
SkipFIR = 1 F
Limit
= 80486 / SF
Bit Name Description Default
R37.3 Zero 0
bin
(see note below) 0
bin
R37.2 Zero 0
bin
0
bin
Do not change these bits
Bits R37.2 and R37.3 always have to be 0
bin
, in order to avoid errors in the A/D converter!
Bit Name Description Default
R37.1 SkipFIR 0
bin
FIR filter is enabled. 0
bin
1
bin
FIR filter is bypassed.
R37.0 Fast 0
bin
Fast Step Mode is disabled. 0
bin
1
bin
Fast Step Mode is active: a fast reaction will follow jumps at
the input, in spite of the filter stage being active. In this case
the filter is bypassed!