Uni-Directional Biss C; Bi-Directional Biss C; Additional Analog, Incremental Real-Time Signal - Balluff BML-S1H1-B/S6-C-M3-A-D0-KA S284 Serie Manual De Instrucciones

BML-S1H1/2-B/S6 _ C-M3 _ A-D0-KA _ _ , _ -S284
Absolute Magnetically Coded Position Measuring System
6
Interfaces (continued)
Uni-directional signal position/logics for BiSS C:
The temporal sequence of the individual bits is shown in
Fig. 6-1 and Fig. 6-4.
6.2.1

Uni-directional BiSS C

Only the data is transmitted from the measuring system to
the controller. No additional information can be or is
transmitted (such as register communication with BiSS C).
CDS/CDM is always high.
After sensor data MSB to LSB, an error and warning bit is
transmitted. The error and warning bit in the data set is
active low. If no error or warning is present, both bits are
high.
6.2.2

Bi-directional BiSS C

With the BiSS C interface, errors/warnings (EW events) are
transmitted in the serial data set. Additionally, the type can
also be queried via register communication.
The error and warning bits are, as with uni-directional
interfaces, transferred in the serial data stream after the
position data and before the CRC. The error and warning
bit in the data set is transferred as active low. If no error or
warning is present, both bits are high.
The reading of a byte requires approx. 50 data frames, i.e.
it takes a finite time until the byte has been read. During
this time, further EW events may occur. They are signalized
instantly in the data set. After the corresponding byte has
been transmitted successfully, the byte can be reread and
the information from the second event be evaluated.
Status register:
Using the register data, the controller can read the exact
error or warning causes. The status registers can be found
at the addresses 0x75 to 0x77. There, different error and
warning causes are coded bit by bit.
Address 0x75:
Bit 6: Configuration error in the EEPROM
Bit 5: Velocity too high
Bit 4: Velocity too high when switching on
Bit 3: Inconsistency error (error in redundancy check)
Address 0x76:
Bit 6: Master track sensor signals too low
► Reduce gap
Address 0x77:
Bit 6: "Nonius" (vernier) track sensor signals too low
► Reduce gap
Bit 2: Segment track sensor signals too low
► Reduce gap
16 english
6.3 Additional analog, incremental real-time
signal
With the analog sine and cosine signals +A (+sin),
−A (−sin), +B (+cos) and −B (−cos), the controller evaluates
the difference in signal amplitudes and, from the signals,
interpolates the precise position within a period (Fig. 6-2).
For a movement over several periods, the controller can
also count the number of periods.
For correct function, the sine signal and the
cosine signal must be evaluated depending on
the direction.
Output voltage
+A (+sin) − (−A (−sin))
+B (+cos) − (−B (−cos))
Signal periods 360° el.
0° 90°
Fig. 6-2: Signals of the sine and cosine sensor (1 mm pole width) in
forward direction
The sensor transmits the measurement as an analog sine/
cosine differential signal with an amplitude of approx. 1 Vss
(peak/peak value) in the nominal range to the controller.
The period is 1 mm.
+A (+Sin)
−A (−Sin)
Fig. 6-3: Circuitry example of subsequent electronics with analog
output
Latch Position
CLK
BiSS
ACK ...Busy... Start CDS MSB
Data
Fig. 6-4: Signals for BiSS C transmission
Distance [µm]
180° 270° 360°
CDM
t
tm
CRC CRC
LSB E W
MSB LSB
t