1st edition, 17-09-2020
7000.05070, 1st edition, 17-09-2020
7000.05070
Product description
11
3.5
Description of the interface
Fig. 4:
Interface signals
The angle information for the singleturn and multiturn position can be queried via a serial
interface with BISS-C protocol. In this case, CLK is the input for the clock signal of the serial
interface. The data of the serial interface is available on the Data line.
The start sequence consists of an acknowledge bit (Ack), a start bit and a control bit (CDS).
All data values are transmitted with the most significant bit first, starting with the
multiturn position (MT15…MT0), followed by the singleturn position (ST11…ST0). This is
followed by an error bit (nERR), a warning bit (nWARN) and 6 CRC bits (CRC5…CRC0).
The error bit is set e.g. by a low battery voltage (see chap. 4.4, p. 24).
The warning bit is activated when the maximum allowed speed is exceeded. nERR and
nWARN are low-active.
If no further clock signals are sent, the encoder enters a timeout after 20
μ
s, causing com-
munication to be ended. The maximum clock frequency is 2 MHz.
For further information on the BISS-C protocol, see: https://biss-interface.com/c/downloads.
The value to which the count of the encoder is reset via the preset pin is not unambig-
uously 0, but instead lies within a range of ±8192 increments, depending on the
singleturn position.
The preset value is set at the factory to a signed interpretation of the position data, see
chap. 6, p. 27. If the position data should be interpreted without sign (unsigned),
another preset value can be set at the factory.
The Data and CLK signals are inverted in relation to the shown Data and CLK signals.
CLK
Data
Ack Start CDS MT15
CRC5
CRC0 Stop
MT0 ST11
ST0 nERR nWARN
Timeout
