IC-LNG_14 Datasheet, PDF (24/30 Pages) IC-Haus GmbH – 16-BIT OPTO ENCODER

iC-LNG 16-BIT OPTO ENCODER ^preliminary
WITH SPI AND SERIAL / PARALLEL OUTPUTS
SYNCHRONIZATION
Rev B1, Page 24/30
iC-LNG synchronizes the digital tracks (DA1 - DA11)
to the interpolator. Data synchronisation operates
successful when the edges of each digital track stay
within the synchronisation range (SR). Ideally, the dig-
ital tracks switch synchronously to the internal sig-
nal D09, respectively, to the zero crossing of cosine.
iC-LNG can correct differences of up to ±45° of one
sine/cosine period from its ideal position. (see Figure
16). However, due to imperfect light levels, code disc
tolerances, etc. only half the maximum synchronisa-
tion range should be utilized during adjustment of the
reticle and code disc.
DPSIN
DPCOS
D09
D0
DA1
(LSB)
SR
SR
DA11
(MSB)
SR
Figure 16: synchronisation range
NSYNC can be used to deactivate synchronization to
check the adjustment or when using a code disc which
is not Gray coded. In this case, the digital track signals
are just comparated and output.
NSYNC
0
1
Add. 0x07, bit 6
Synchronization activated
Synchronization deactivated
Table 22: Synchronization
PARALLEL ENCODER MODE
In parallel encoder mode an absolute position data
word with a width of 14 bits is output in parallel. This
position data word consists of the 11 bits of the digital
tracks and of 3 bits interpolated from the analog track.
The position data is output in Gray code. Parallel en-
coder mode is activated by parameter EPG (see also
Operating Modes on page 17).
EPG
0
1
Add. 0x07, bit 4
Interface mode
Parallel encoder mode
Table 23: Selecting the operating mode