IC-LNB_16 Datasheet, PDF (22/37 Pages) IC-Haus GmbH – 18-BIT OPTO ENCODER

iC-LNB 18-BIT OPTO ENCODER ^preliminary
WITH SPI AND SER/PAR INTERFACES
PACTIVE
Code
0
1
Description
Sensor data channel deactivated
Sensor data channel activated
Table 12: Sensor data activation
CS
SCLK
MOSI
MISO
REQ
OP
OP
Rev B2, Page 22/37
SD1 SD2 SD3
If PACTIVE is not set, on commands Sensor data sta-
tus or Sensor data transmission the ERROR bit is
set in the STATUS byte (Table 14), indicating that the
command has not been carried out. The slave immedi-
ately outputs the data at MISO which has been sent by
the master through MOSI.
If only one slave is connected up with one register and
one sensor data channel, it must be ensured that the
RACTIVE and PACTIVE bits are last in the data byte
(Figure 7).
NB: daisy chain
If the slaves are connected in a chain (full duplex
chain), with this command the master can determine
the number of connected register and sensor data
channels. To this end it can send a 1 after the OP-
CODE, which is repeated at MISO after the number
of register and sensor data channels (see Figure 7).
8 cycles
Figure 8: SDAD transmission: read SD
With command Sensor data transmission the master
can not only read sensor data (SD) out from the slave;
at the same time it can also transmit actuator data (AD)
to the slave. iC-LNB ignores the transmitted actuator
data.
REQ
CS
SCLK
MOSI
OP
AD1 AD2 AD3
MISO
OP
SD1 SD2 SD3
8 cycles
Figure 9: SDAD transmission: read SD, write AD
CS
SCLK
MOSI
MISO
OP
1 0 0 0 0 0 RA PA
OP
00100000
8 cycles
RACTIVE / PACTIVE vector
Sensor data status
Should the master not know the processing time, it can
request sensor data using the command Sensor data
status. iC-LNB does not need any processing time;
therefore, SVALID is always valid.
The command causes
Figure 7: Setting ACTIVATE: RACTIVE/PACTIVE
(one slave)
1. all slaves activated with PACTIVE to switch their
SVALID register between MOSI and MISO.
Sensor data transmission
iC-LNB latches its position data on the first rising edge
at SCLK if CS is switched to 1 (REQ). The sensor data
shift register is switched between signals MOSI and
MISO for SPI communication and can then be clocked
out. The size of the sensor data shift register must
be set to 18 bits (see section on shift register output,
page 31). The position data is always Gray coded and
is output with the MSB first. Byte SD3 (Figure 8) is then
filled with zeroes.
If invalid data is sampled in the shift register, the
ERROR bit is set in the STATUS byte (Tab. 14) and
zeroes are output as the data word.
2. The next request for sensor data, triggered on
the first rising edge at SCLK when CS has again
been set to 1, is ignored by the slave.
The end of conversion is signaled by SVALID (SV). With
this command the master can poll to the end of con-
version. The sensor data is readout on the command
SDAD transmission.
SVALID
Code
0
1
Description
Sensor data channel invalid
Sensor data channel valid
Table 13: Sensor data valid indication