HEIDENHAIN EnDat 2.2 Manual

Digital drive systems and feedback loops with position encoders for measured value acquisition require fast data transfer with high
transmission reliability from the encoders. Further data such as drive-specific parameters, compensation tables, etc. must also
be made available. For high system reliability, the encoders must be integrated in routines for error detection and have diagnostic
capabilities.
The EnDat interface from HEIDENHAIN is a digital, bidirectional interface for encoders. It is capable both of transmitting position values
from incremental and absolute encoders as well as transmitting or updating information stored in the encoder, or saving new information.
Thanks to the serial transmission method, only four signal lines are required. The data are transmitted in synchronism with the clock
signal from the subsequent electronics. The type of transmission (position values, parameters, diagnostics, etc.) is selected through
mode commands that the subsequent electronics send to the encoder. The EnDat 2.2 interface, a purely serial interface, is also suited for
safety-related applications up to SIL 3.
Technical Information
EnDat 2.2 – Bidirectional Interface for Position Encoders
Voltage supply
CLOCK 16 MHz
DATA Position values, parameters, datum shifts,
electronic ID label, diagnostics, warning, etc.

2
The EnDat interface provides everything
needed to reduce system cost and at the
same time improve your technical standard.
The most significant benefits are:
Cost optimization
• A single interface for all absolute and
incremental encoders
• Simple subsequent electronics with
EnDat receiver chip and standard
components
• Simpler, more economical voltage
supply, since remote sensing is not
required
• Simple connection technology: Standard
connecting elements (M12 – 8-pin),
single shielded standard cables and low
wiring costs
• Only one cable with HMC 6: the Hybrid
Motor Cable contains the lines for the
encoder, the motor and the brake
• Small motor or system dimensions
through compact connecting elements
• No expensive additional sensory analysis
and wiring: EnDat 2.2 transmits additional
data (limit switch, temperature, etc.)
• Faster configuration during installation:
Datum shifting through offsetting by a
value in the encoder
Improved quality
• Higher system accuracy through specific
optimization in the encoder
• High contour accuracy, particularly for
CNC machine tools: position value
formation in the encoder permits shorter
sampling intervals without influencing
the computing time of the CNC
Higher availability
• Automatic configuration of the system
axis: all necessary information can be
saved in the encoder (electronic ID label).
• High system reliability through purely
digital data transmission
• Diagnostics of the encoders through
monitoring messages and warnings that
can be evaluated in the subsequent
electronics
• High transmission reliability through
cyclic redundancy checking
Safety system
• EnDat 2.2 was conceived for safety-
related machine designs up to SIL 3
• Two independent position values for
error detection
• Two independent error messages
• Checksums and acknowledgments
• Forced dynamic sampling of error
messages and CRC formation by
subsequent electronics
Support for state-of-the-art machine
designs
• Suitable for direct drive technology
thanks to high resolution, short cycle
times and commutation information
• Cyclic sampling every 25 µs with full
“read and write” mode
• Position values available in the subse-
quent electronics after only approx. 10 µs
Miniature connecting
element, M12, 8-pin
Simple connection technology,
8-wire cable, single shielding
Integrated interpolation and position value
formation, temperature measurement
Connecting element,
e.g. M12, D-sub
Voltage supply without
remote sensing
(UP= 3.6 to 5.25 V or
3.6 to 14 V)
Simple subsequent electronics
with EnDat 2.2 receiver chip
(“EnDat Master”)
* For parallel voltage supply lines
or battery buffering
Benefits of the EnDat interface
For further information on implementing
EnDat or additional documents, see
www.endat.de

3
–The bidirectional interface
Interface EnDat serial bidirectional
Data transfer Position values, parameters and additional data
Data input Differential line receiver according to EIA standard RS 485 for
the signals CLOCK, CLOCK, DATA and DATA
Data output Differential line driver according to EIA standard RS 485 for
DATA and DATA signals
Position values Ascending during traverse in direction of arrow (see dimensions
of the encoders)
Incremental signals Depends on encoder
»1 VPP
, TTL, HTL (see the respective incremental signals)
The EnDat interface is a digital,
bidirectional interface for encoders. It is
capable both of transmitting position
values as well as transmitting or updating
information stored in the encoder, or saving
new information. Thanks to the serial
transmission method, only four signal
lines are required. The data is transmitted
in synchronism with the clock signal from
the subsequent electronics. The type of
transmission (position values, parameters,
diagnostics, etc.) is selected through mode
commands that the subsequent electronics
send to the encoder. Some functions are
available only with EnDat 2.2 mode
commands.
History and compatibility
The EnDat 2.1 interface available since the
mid-90s has since been upgraded to the
EnDat 2.2 version (recommended for new
applications). EnDat 2.2 is compatible in its
communication, command set and time
conditions with version 2.1, but also offers
significant advantages. It makes it possible,
for example, to transfer additional data (e.g.
sensor values, diagnostics, etc.) with the
position value without sending a separate
request for it. This permits support of
additional encoder types (e.g. with battery
buffer, incremental encoders, etc.). The
interface protocol was expanded and the
time conditions (clock frequency,
processing time, recovery time) were
optimized.
Supported encoder types
The following encoder types are currently
supported by the EnDat 2.2 interface (this
information can be read out from the
encoder’s memory area):
• Incremental linear encoder
• Absolute linear encoder
• Rotational incremental singleturn
encoder
• Rotational absolute singleturn encoder
• Multiturn rotary encoder
• Multiturn rotary encoder with battery
buffer
In some cases, parameters must be
interpreted differently for the various
encoder models (see EnDat Specifications)
or EnDat additional data must be
processed (e.g. incremental or battery-
buffered encoders).
Order designations
The order designations define the central
specifications and give information about:
• Typical voltage supply range
• Command set
• Availability of incremental signals
• Maximum clock frequency
The second character of the order
designation identifies the interface
generation. For encoders of the current
generation the order designation can be
read out from the encoder memory.
Incremental signals
Some encoders also provide incremental
signals. These are usually used to increase
the resolution of the position value, or to
serve a second subsequent electronics
unit. Current generations of encoders have
a high internal resolution, and therefore no
longer need to provide incremental signals.
The order designation indicates whether an
encoder outputs incremental signals:
• EnDat01 With 1 VPP incremental signals
• EnDatH With HTL incremental signals
• EnDatT With TTL incremental signals
• EnDat21 Without incremental signals
• EnDat02 With 1 VPP incremental signals
• EnDat22 Without incremental signals
Note on EnDat01/02:
The signal period is stored in the encoder
memory.
Voltage supply
The typical voltage supply of the encoders
depends on the interface:
EnDat01
EnDat21
5 V ± 0.25 V
EnDat02
EnDat22
3.6 V to 5.25 V or 14 V
EnDatH 10 V to 30 V
EnDatT 4.75 V to 30 V
Exceptions are documented in the
Specifications.
Command set
The command set describes the available
mode commands, which define the
exchange of information between the
encoder and the subsequent electronics.
The EnDat 2.2 command set includes all
EnDat 2.1 mode commands. In addition,
EnDat 2.2 permits further mode com-
mands for the selection of additional data,
and makes memory accesses possible
even in a closed control loop. When a
mode command from the EnDat 2.2
command set is transmitted to an encoder
that only supports the EnDat 2.1 command
set, an error message is generated. The
supported command set is stored in the
encoder’s memory area:
• EnDat01/21/H/T Command set 2.1
or 2.2
• EnDat02/22 Command set 2.2

4
Cable length [m]

Clock frequency [kHz] 
EnDat 2.1; EnDat 2.2 without propagation-delay compensation
EnDat 2.2 with propagation-delay compensation
Under certain conditions, cable lengths up to 300 m are possible after consultation with
HEIDENHAIN
Additional data
One or two items of additional data can be
appended to the position value, depending
on the type of transmission (selection via
MRS code). The additional data supported
by the respective encoder are saved in the
encoder parameters.
The additional data contains:
Status information, addresses and data
• WRN – warnings
• RM – reference mark
• Busy – parameter request
Additional data 1
• Diagnostics
• Position value 2
• Memory parameters
• MRS-code acknowledgment
• Test values
• Temperature
• Additional sensors
Additional data 2
• Commutation
• Acceleration
• Limit position signals
• Asynchronous position value
• Operating status error sources
• Timestamp
Clock frequency
The clock frequency is variable—depending
on the cable length (max. 150 m)—
between 100 kHz and 2 MHz. With
propagation-delay compensation in the
subsequent electronics, either clock
frequencies up to 16 MHz are possible or
cable lengths up to 100 m. For EnDat
encoders with order designation EnDat x2,
the maximum clock frequency is stored in
the encoder memory. For all other encoders
the maximum clock frequency is 2 MHz.
Propagation-delay compensation is provid-
ed only for order designations EnDat 21
and EnDat 22; for EnDat 02, see the note
below.
EnDat01
EnDatT
EnDatH
≤2 MHz (see “without
propagation-delay com-
pensation” in the diagram)
EnDat21 ≤2 MHz
EnDat02 ≤2 MHz or
≤8 MHz or 16 MHz
(see note)
EnDat22 ≤8 MHz or 16 MHz
Transmission frequencies up to 16 MHz in
combination with large cable lengths place
high technological demands on the cable.
Due to the data transfer technology, the
adapter cable connected directly to the
encoder must not be longer than 20 m.
Greater cable lengths can be realized with
an adapter cable no longer than 6 m and
an extension cable. As a rule, the entire
transmission path must be designed for
the respective clock frequency.
Note on EnDat02
EnDat02 encoders can feature a pluggable
cable assembly. In choosing the version
of the adapter cable, the customer also
decides whether the encoder will be
operated with incremental signals or
without them. This also affects the
maximum possible clock frequency. For
adapter cables with incremental signals the
clock frequency is limited to at most
2 MHz; see EnDat01. For adapter cables
without incremental signals the clock
frequency can be up to 16 MHz. The exact
values are stored in the encoder’s memory.
Position values
The position value can be transmitted with
or without additional data.
It is not transmitted to the subsequent
electronics until after the calculation time
tcal has passed. The calculation time is
ascertained at the highest clock frequency
permissible for the encoder, but at no
greater than 8 MHz.
Only the required number of bits is trans-
ferred for the position value. The bit num-
ber depends on the respective encoder
and can be read out from the encoder for
automatic parameterization.
Typical operating modes
Operating mode EnDat 2.1: This mode is
for encoders that provide additional incre-
mental signals. The absolute position is
read out once simultaneously with the
incremental position and both are used to
calculate the position value. Otherwise, the
position value in the control loop is formed
on the basis of the incremental signals.
Only EnDat 2.1 mode commands are used.
Operating mode EnDat 2.2: This mode is
for purely serial encoders. The position
value is read out from the encoder in each
control cycle. EnDat 2.2 mode commands
are typically used to read out the position
value. EnDat 2.1 mode commands are
typically used to read and write parameters
after switch-on.
The EnDat 2.2 interface can interrogate the
position and additional data, and also per-
form functions (e.g. read/write parameters,
reset error messages, etc.), all within the
closed loop.

5
Absolute encoder Subsequent electronics
»1 VPP A*)
»1 VPP B*)
Operating
parameters
Operating
status
Parameters
of the OEM
Parameters of the encoder
manufacturer for
EnDat 2.1 EnDat 2.2
*) Depends on encod-
er, example repre-
sentation for 1 VPP
Absolute
position value
EnDat interface
Incremental
signals *)
Memory areas
The encoder provides several memory
areas for parameters. These can be read
from by the subsequent electronics, and
some can be written to by the encoder
manufacturer, the OEM, or even the end
user. The parameter data are stored in a
permanent memory. This memory permits
only a limited number of write access
events and is not designed for cyclic data
storage. Certain memory areas can be
write-protected (this can only be reset by
the encoder manufacturer).
Parameters are saved in various memory
areas, e.g.:
• Encoder-specific information
• Information of the OEM
(e.g. “electronic ID label” of the motor)
• Operating parameters (datum shift,
instruction, etc.)
• Operating status (alarm or warning
messages)
Monitoring and diagnostic functions of
the EnDat interface make a detailed
inspection of the encoder possible.
• Error messages
• Warnings
• Online diagnostics based on valuation
numbers (EnDat 2.2)
• Mounting interface
Input circuitry of
subsequent electronics
Dimensioning
IC1= RS 485 differential line receiver
and driver
Z0= 120 
Encoder Subsequent electronics
1 VPP
Data transfer
Incremental signals
Depends on encoder
(e.g. 1 VPP)
Functional safety – Basic principle
EnDat 2.2 strictly supports the use of
encoders in safety-related applications. The
DIN EN ISO 13 849-1 (previously EN 954-1),
EN 61508 and EN 61800-5-2 standards
serve as the foundation. These standards
describe the assessment of safety-related
systems, for example based on the failure
probabilities of integrated components and
subsystems. The modular approach helps
manufacturers of safety-related systems to
implement their complete systems,
because they can begin with prequalified
subsystems.
For more information, see “Functional
safety” at www.endat.de

S
CRC
F1 D D D D
CRC CRC CRC CRC
2T 2T
0
S
CRC
0 0 1 1 1
0 0 0 1 1 1
F1 D
t
D
D D D
CRC CRC CRC CRC
6
A clock pulse (CLOCK) is transmitted by
the subsequent electronics to synchronize
data transmission. When not transmitting,
the clock signal is on high level.
Clock frequency and cable length
Without propagation-delay compensation,
the clock frequency is variable between
100 kHz and 2 MHz, depending on the
cable length. Because large cable lengths
and high clock frequencies increase the
signal run time to the point that they can
disturb the unambiguous assignment of
data, the delay can be measured in a test
run and then compensated. With this
propagation-delay compensation in the
subsequent electronics, clock frequencies
up to 16 MHz are possible at cable lengths
up to a maximum of 100 m (fCLK  8 MHz).
The maximum clock frequency is mainly
determined by the cables and connecting
elements used. To ensure proper function
at clock frequencies above 2 MHz, use only
original HEIDENHAIN cables.
The permissible clock frequencies shown
in the diagrams apply for a clock on-off
ratio of 1:1. This means that the HIGH and
LOW levels of the clock are equally long.
For other on-off ratios, the theoretical clock
frequency is calculated as fc =
Determining the propagation time
After every change in the transmission line
hardware, the propagation time must be
ascertained—preferably automatically after
every power interruption.
The subsequent electronics transmit the
mode command Encoder transmit position
values without additional data to the
encoder. After the encoder has switched
to transmission, i.e. after in total 10 clock
periods, a counter in the subsequent
electronics starts with every rising edge.
The subsequent electronics measure the
propagation time as the difference
Clock frequency
Clock frequency [kHz]
Cable length [m]
Without delay compensation
With delay compensation
Clock on-off ratio
Clock
between the last rising clock pulse edge
and the edge of the start bit. The process
should be repeated at least three times in
order to rule out any disturbances during
the calculation of the propagation time and
to test the value for consistency. The signal
propagation time is measured at a reduced
clock frequency (100 kHz to 200 kHz). To
attain sufficient accuracy, however, the
value must be sampled at an internal
frequency that is at least eight times higher
than the clock frequency to be used later
for data transmission.
1
2tmin
Clock pulse
transmitted
to the encoder
Clock pulse
at encoder
Data at
encoder
Start counter
Data at subs.
electronics
Mode
Mode command
Clock frequency 100 kHz to 200 kHz
S= start, F1 = error, D= data
Data transfer
Under certain conditions, cable lengths up to 300 m are possible after consultation with HEIDENHAIN.

7
Transmitted data are identified as either
position values, position values with
additional data, or parameters. The type of
information to be transmitted is selected
by mode commands. Mode commands
define the content of the transmitted
information. Every mode command
consists of three bits. To ensure reliable
transmission, every bit is transmitted
redundantly (inverted or double). If the
encoder detects an incorrect mode
transmission, it transmits an error message.
The EnDat 2.2 interface can also transfer
parameter values in the additional data
together with the position value. This
makes the current position values
constantly available for the control loop,
even during a parameter request.
Mode bit
No. Mode command M2 M1 M0 (M2) (M1) (M0)
1Encoder send position values
EnDat 2.1 command set
EnDat 2.2 command set
000111
2Selection of memory area 001110
3Encoder receive parameters 011100
4Encoder send parameters 100011
5Encoder receive reset 101010
6Encoder send test values 010101
7Encoder receive test command 110001
8Encoder send position value with
additional data
111000
9Encoder send position value and
receive selection of memory area 1) 001001
10 Encoder send position value and
receive parameters1) 011011
11 Encoder send position value and
send parameters1) 100100
12 Encoder send position value and
receive error reset1) 101101
13 Encoder send position value and
receive test command1) 110110
14 Encoder receive communication
command 2) 010010
1) Selected additional data are also transmitted
2) Reserved for encoders that do not support the safety system
The time encoders need for calculating
the position values tcal sometimes differs
depending on whether EnDat 2.1 or
EnDat 2.2 mode commands are transmit-
ted (see catalog: Linear Encoders for
Numerically Controlled Machine Tools –
Specifications). If the incremental signals
are evaluated for axis control, then the
EnDat 2.1 mode commands should be
used. Only in this manner can an active
error message be transmitted synchro-
nously with the currently requested
position value. EnDat 2.1 mode commands
should not be used for purely serial
position-value transfer for axis control.
Selecting the transmission type

8
For every data transfer one data packet is
transmitted in synchronism with the clock
signal. The transmission cycle begins with
the first falling clock edge. The encoder
saves the measured values and calculates
the position value.
After two clock pulses (2T), the subsequent
electronics transmit the mode command
Encoder transmit position value (with/
without additional data).
After successful calculation of the absolute
position value (tcal—see table), the start
bit begins the data transmission from the
encoder to the subsequent electronics.
The subsequent error bits, error 1 and
error 2 (only with EnDat 2.2 commands),
are group signals for all monitored
functions and serve for failure monitoring.
They are generated separately from each
other and indicate when a malfunction of
the encoder can result in incorrect position
values. The exact cause of the disturbance
is saved in the “operating status” memory
of the encoder and can be interrogated in
detail.
The encoder then transmits the position
value, beginning with the LSB. Its length
varies depending on which encoder is
being used. The number of required clock
pulses for transmission of a position value
is saved in the parameters of the encoder
manufacturer.
The data transmission of the position value
is completed with the Cyclic Redundancy
Check (CRC).
This is followed in EnDat 2.2 by the
additional data 1 and 2, each also
concluded with a CRC. The content of
the additional data is determined by the
selection of the memory area and is
transmitted in the next sampling cycle for
additional data. This information is then
transmitted with every sample until a
selection of a new memory area changes
the content.
With the end of the data word, the clock
must be set to HIGH. After 10 to 30 µs or
1.25 to 3.75 µs (with EnDat 2.2 parameter-
izable recovery time tm) the data line falls
back to LOW. Then a new data transmis-
sion can be initiated by starting the clock.
Position value packet without additional data
Encoder saves
position value
Subsequent electronics
transmit mode command
Mode command Position value CRC
S= start, F1 = error 1, F2 = error 2, L= LSB, M= MSB
Diagram does not include the propagation-delay compensation
Without delay compensation With delay compensation
Clock frequency fc100 kHz ... 2 MHz 100 kHz ... 16 MHz
Calculation time for
Position value
Parameters
tcal
tac
Typical of EnDat 2.2 encoders: 5 µs
Max. 12 ms
Recovery time tmEnDat 2.1: 10 µs to 30 µs
EnDat 2.2: 10 µs to 30 µs or 1.25 µs to 3.75 µs (fc1 MHz)
(parameterizable)
tRMax. 500 ns
tST –2 µs to 10 µs
Data delay time tD(0.2 + 0.01 x cable length in m) µs
Pulse width tHI
tLO
0.2 µs to 10 µs
0.2 ms to 50 ms
Up to 30 µs
(with LC 1x3/4x3)
Pulse width fluctuation
HIGH to LOW max. 10 %
Position values

9
Data packet with position value and additional data 1 and 2
Encoder saves
position value
Subsequent electronics
transmit mode command
Mode command Position value CRC Additional datum 2 Additional datum 1
CRC CRC
S= start, F1 = error 1, F2 = error 2, L= LSB, M= MSB
Diagram does not include the propagation-delay compensation
Content of the data packet
Error messages 1 and 2
The EnDat interface enables
comprehensive monitoring of the encoder
without requiring an additional transmission
line. An error message becomes active if a
malfunction of the encoder might result in
incorrect position values. At the same time,
the cause of error is saved in the encoder.
Errors include:
• Light unit failure
• Signal amplitude too low
• Error in calculation of position value
• Supply voltage too high/low
• Current consumption is excessive
For reasons of security it is necessary to
generate a second, independently acquired
error message. It is transmitted with the
inverted value as error message 2. The two
error messages must be evaluated
separately from each other.
Position value
The position value is transmitted as a
complete data word whose length
depends on the resolution of the encoder.
Transmission begins with the LSB (LSB
first).
The composition of the position value
differs depending on the encoder model
(see EnDat specifications). At this point,
absolute encoders transmit the absolute
position value while incremental encoders
transmit the relative position value (see
also “Position value 2“ on the following
page).
Additional data
An encoder with EnDat 2.2 interface can
transmit the position value together with
up to two additional data. Sixteen possible
contents identified by unique numbers are
assignable to each of the additional data 1
and 2. These numbers are used to select
the additional data and are transmitted for
acknowledgment (see next page). The
additional data supported by the encoder is
saved in the encoder memory.
The “Encoder transmit position value and
receive selection of memory area” mode
command selects the information to be
transmitted, which is therefore possible in
a closed loop. After the additional datum
has been selected, it is transmitted with
the next mode command (only no. 8 to 13).
The additional datum is transmitted with
each position value until it is deselected
through the transmission of a special MRS
code or until another additional datum is
selected. When the encoder is switched
on, at first no additional data is selected.
Example
Additional datum 1:
Rolling transmission of temperature 1 (Temp1: MRS code 0x4C) and temperature 2 (Temp2: MRS code 0x4D)
Additional datum 2: Transmission of the operating status error sources (BZFQ: MRS code 0x59)
Mode command 9 (001001): “Encoder transmit position value and receive selection of memory area”
Subsequent electronics àencoder Encoder àsubsequent electronics
Mode command 9 + MRS code 0x59 Position
Mode command 9 + MRS code 0x4C Position + BZFQ
Mode command 9 + MRS code 0x4D Position + BZFQ + Temp1
Mode command 9 + MRS code 0x4C Position + BZFQ + Temp2
Mode command 9 + MRS code 0x4D Position + BZFQ + Temp1
etc.

10
Status data
WRN – warnings
This collective bit indicates whether certain
tolerance limits of the encoder have been
reached or exceeded, for example
rotational speed or light source control
reserve, without necessarily indicating an
incorrect position value. This function
makes it possible to issue preventive
warnings in order to minimize idle time.
The cause of the warning is stored in the
encoder memory. The error messages and
warnings supported by the respective
encoder are saved in the “parameters of
the encoder manufacturer” memory area.
RM – reference mark
The RM bit indicates whether the
reference run has been completed. In
incremental systems, this is required in
order to establish the absolute reference
to the machine reference system. The
absolute position value can then be read
from the additional datum 1. On absolute
encoders, the RM bit is always on HIGH.
Busy – parameter request
When LOW, the busy bit indicates that a
parameter request (read/write) is possible.
If a request is being processed (HIGH), the
encoder memory must not be accessed.
Content of the additional data
The content of the additional data is
defined by the mode command for
selection of a memory area. This content,
updated with each clock pulse, is
transmitted until there is a new request.
A unique number is assigned to each
additional datum. It is 5 bits in length and
is transmitted for inspection purposes. The
following contents are possible:
Additional datum 1
• Diagnostics
Cyclic information on encoder function
and additional diagnostic values, such as
mounting information
• Position value 2
For incremental encoders: Relative
position information (counter starts from
zero at switch-on). The absolute position
value is only available after the reference
marks have been traversed (RM bit
HIGH).
For absolute encoders: Second absolute
position value for safety-related
applications.
• Memory parameters
Parameters saved in the encoder can
also be transmitted along with the
position values. The request is defined
via memory range selection, followed by
output of the parameters with the
associated address.
• MRS code—acknowledgment
Acknowledgment of the requested
memory area selection
• Test values
Test values serve for inspection purpos-
es, in service diagnostics, for example.
• Temperature
Transmission of temperature in encoders
with integrated evaluation of internal or
external temperature sensors.
• Additional sensors
The EnDat 2.2 protocol enables the
connection of 16 additional sensors (4-bit
address). The sensor values are output in
a rolling request process (x+1); the
assigned sensor can be identified based
on the supplied address.
Additional datum 2
• Commutation
Some incremental encoders provide
“rough” position information for
commutation in electric motors.
• Acceleration
If the encoder has additional sensor
systems for acceleration measurement,
it can transmit the results.
• Limit position signals
Limit position signals and homing
information.
• Asynchronous position value
Position formed by oversampling
between two "regular" requests.
• Operating status error sources
Detailed information about the cause of
the present error message.
• Timestamp
Reserved for touch probes.
30 bits
Additional data 5 bits
CRC
Acknowledgment of
additional data 8 bits
address or
data
8 bits data
Additional data
One or two items of additional data can be
appended to the position value, depending
on the type of transmission (selection via
MRS code). The additional data are each
30 bits in length, with a LOW level as first
bit. Each additional datum is concluded
with a CRC that is formed from the respec-
tive additional data without the first bit or
the CRC.
The additional data supported by the
respective encoder are saved in the
encoder parameters.
The additional data include status
information, addresses, and data: