Eds - Balluff BML-S1G0-B7-M5E-0-S284 Serie Betriebsanleitung

BML-S1G0-B/S7_ _-M5E_-_0-(SA26-)S284
Absolute Magnetically Coded Position Measuring System
6
Interfaces (continued)
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).
Uni-directional signal position/logics for BiSS C:
The temporal sequence of the individual bits is shown in
Fig. 6-3.
CDS/CDM is always high, followed by four null bits. 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/warning is present, both bits are
high.
Bi-directional BiSS C
With the BiSS C interface, as with the SSI interface, errors/
warnings (EW events) are transferred in the serial data set.
Additionally, the event type is not only signaled by the
LEDs, but 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 picture in
section 6.2 shows the temporal relationships. The error
and warning bit in the data set is transferred as active low.
If no error/warning is present, both bits are high.
After the error/warning byte has been read, it is
automatically deleted in the BML. If the event is still present
(corresponding bits continue to be transmitted), the byte is
reset and can be re-read. The byte is no longer reset once
the event is no longer present.
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.
Error byte, warning byte:
Using the register data, the controller can read the exact
error or warning causes. The error byte is located at the
BiSS address 0x48 and the warning byte at BiSS address
0x49. There, different error and warning causes are coded
bit by bit. For the meaning of the errors/warnings, see
section 8 on page 27.
Trigger time
Clk
BiSS
Data ACK ... Busy . ..
Fig. 6-3: BiSS C interface signals (uni-directional)
www.balluff.com
Null bit Null bit Null bit Null bit
Start CDS
6.2.3

EDS

EDS, electronic data sheet, user area:
This BiSS C function allows the customer to permanently
store and read out, byte by byte, any customer-specific
data in the EEPROM user area of the sensor head via
register communication.
The entire BiSS address space is divided into three areas:
– Hidden
The customer has no access. This is where e.g.
internal configuration data is stored.
– Read Only (EDS area)
This area is read-only.
Read/Write (user area)
–
This area has a total of 448 bytes (7 banks, each with
64 bytes). Mechanical assembly data for the sensor
head, the assembly date, order designation for the
sensor head, etc. can be stored here.
Register communication runs in the background of the
BiSS C data transfer. Without interfering with the real-time
properties of the position data, register data in the sensor
head can also be written and read out at certain
addresses. For further information,
see: www.biss-interface.com/
The BiSS register address space (0x00 to 0x7F) is divided
into two areas:
1. A fixed area which is always accessible in write and
read mode (0x40 to 0x7F). This area can be used to
select the bank that is to be edited at any point in time.
The following information can be read out
simultaneously:
– Is an error/warning present?
– Which error/warning is present?
– At which bank is the electronic data sheet located?
– Which bank has been selected from the switchable
bank area?
2. A switchable bank area (0x00 to 0x3F) that displays
different EEPROM areas depending on the selected
bank. Depending on the bank, there may be no
access, or "read only" or "read and write" access. The
selected bank is entered at address 0x40. In the
register address area
0x00 to 0x3F, the corresponding bank is displayed.
Fig. 6-4 shows the principle of relationships.
CRC
MSB LSB E W
MSB
CDM
t m
t
CRC
LSB
t t
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