Mode parameters and CycleCount parameters
P 576[0] - ENC_CH3_Mode can be used to run a parity evaluation after the data. In
addition, ENC_CH3_Mode makes it possible to run special SSI encoders that deliver
one or more special bits after the data. In this case, the ServoOne will not evaluate
these bits – this mode is meant to make it possible to work with SSI encoders that
require for these bits to be sampled. P 636[0] - ENC_CH3_CycleCount makes it
possible to run slower SSI encoders that cannot handle the required cycle of 125 µs.
The control characteristics will deteriorate when using this type of SSI encoder,
which is why doing so is
not recommended.
ID
Index Name
Unit Description
507
ENC_CH3_Sel = 2
=SSI(2)
573
0
ENC_CH3_MultiT
Number of MultiTurn bits (absolute encoder)
574
0
ENC_CH3_SingleT
Number of SingleTurn bits (absolute encoder)
575
0
ENC_CH3_Code
Code selection (SSI absolute encoder)
576
0
ENC_CH3_Mode
Mode selection (SSI absolute encoder)
584
0
ENC_CH3_MTBase
Minimum MultiTurn position (SSI absolute
encoder)
585
0
ENC_CH3_MTEnable
Channel 1: Multi-turn as single-turn
600
0
ENC_CH3_Position
inc
Position encoder channel 1
636
0
ENC_CH3_CycleCount
Channel 3: Position encoder sampling cycle (n x
125 µsec)
Table 6.26: Encoder configuration channel 3 (X8) - SSI parameters
The Sel, Lines, MultiT and SingleT parameters are self-explanatory.
Other parameters, such as MTBase and MTEnable, are described elsewhere (see
Section "Channel 3: Interface X8 (optional)" on page 78 and Section "SinCos /
NOTE
l
Linear SSI encoders will be treated as rotary SSI encoders. In this
case, it is impossible to determine that the system is a linear
encoder system based on the encoder head.
ID No.: 0842.26B.5-01 Date: 09.2020
ServoOne - Device Help
90
6 Encoder
l
P 573[0] - ENC_CH3_MultiT
= Number of multi-turn bits: 0..14
Due to the design of the cyclical SSI interface as a motor feedback interface,
the number of multi-turn bits is limited to 14 (no limit to 14 bits in the case of a
SinCos interface with SSI one-time reading).
l
P 575[0] - ENC_CH3_Code
= SSI decoding: BINARY(0) or GRAY(1)
Gray decoding will be selected by default. The other option is to use binary
decoding.
l
P 576[0] - ENC_CH3_Mode
= Available SSI auxiliary settings
This parameter has a 16-bit hex value. With the default setting (0000h), SSI
wire break monitoring will be enabled. A value of 0001h will disable SSI wire
break monitoring, meaning that one bit less will be read.
Following is a list of what some of the terms in the table below stand for:
o
Data = Sequence of all data bits
o
EncObs = Wire break bit
o
Nothing = No bit
o
POdd = Odd parity bit
o
PEven = Even parity bit
o
Free = A free bit
ID
Value Name
576
ENC_CH3_Mode
0000h Data_EncObs
Default: with wire break
0001h Data_Nothing
0002h Data_POdd_EncObs
ODD Parity
0003h Data_Free_POdd_EncObs
0004h Data_POdd
0005h Data_Free_POdd
0006h Data_Free_EncObs
0007h Data_Free_Free_EncObs
000Ch Data_PEven_EncObs
EVEN Parity
Table 6.27: SSI mode parameters (all other values are reserved)