IFM Electronic Efector 400 RN30 Series Application guide

Device manual
Profibus encoder
RM30xx
RN30xx
706355/00 06/2013
UK

Encoder with Profibus interface
2
Contents
1 Preliminary note � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 4
1�1 Symbols used� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 4
1�2 Warning signs used � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 4
1�3 Notes on this document � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 4
2 Safety instructions � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 4
3 General information � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 5
3�1 1�2 Profibus technology � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 5
4 Functions and features � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 5
5 Electrical connection� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 6
5�1 Connection of the signal and supply cables � � � � � � � � � � � � � � � � � � � � � � � � 6
6 Installation� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 6
7 Installation� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 7
7�1 Settings in the terminal cap � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 7
7�1�1 Participant address � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 7
7�1�2 Bus termination � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 7
8 Device configuration � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 8
9 Encoder classes � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 8
9�1 Class 1 and Class 2 � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 8
9�2 Parameter setting � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 9
9�2�1 Class 2 functionality � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 9
9�2�2 Commissioning diagnostics � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 9
9�2�3 Scaling function � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 10
9�2�4 Measuring steps per revolution � � � � � � � � � � � � � � � � � � � � � � � � � � � � 10
9�2�5 Total resolution � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 10
9�3 Data exchange during normal operation � � � � � � � � � � � � � � � � � � � � � � � � � �11
9�3�1 Transfer of the process actual value � � � � � � � � � � � � � � � � � � � � � � � � �11
9�3�2 Preset function � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 12
10 Profibus encoder profile Class 2� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 13
10�1 Parameters� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 14
10�1�1 Activation of the manufacturer-specific parameters � � � � � � � � � � � � 14
10�1�2 Requested measuring steps � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 14
10�1�3 Required resolution � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 15
10�1�4 Activate set-up mode � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 16
10�1�5 Reduced diagnosis � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 17
10�1�6 Software limit switch� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 17
10�1�7 Physical measuring steps � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 18
10�1�8 Encoder type � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 18
10�1�9 Unit of measurement velocity� � � � � � � � � � � � � � � � � � � � � � � � � � � � � 19
10�2 Data exchange during normal operation � � � � � � � � � � � � � � � � � � � � � � � � 19
10�3 Set-up mode� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 20

UK
Encoder with Profibus interface
3
10�3�1 Set the direction of rotation � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 21
10�4 Start teach operation � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 21
10�4�1 Stop teach operation � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 21
10�4�2 Preset value � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 23
11 Diagnostic messages � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 24
11�1 Overview� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 24
11�2 Supported diagnostic messages � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 25
11�2�1 Extended diagnostic header� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 25
11�2�2 Memory error � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 25
11�2�3 Operating status � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 25
11�2�4 Encoder type � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 25
11�2�5 Singleturn resolution� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 25
11�2�6 Number of revolutions � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 26
11�2�7 Operating time alarm � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 26
11�2�8 Profile version� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 26
11�2�9 Software version� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 26
11�2�10 Operating time � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 26
11�2�11 Zero point shift � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 26
11�2�12 Configured resolution � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 26
11�2�13 Configured total resolution � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 26
11�2�14 Serial number � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 27
12 LED indicators � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 27
12�1 Legend � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 27
13 Configuring with STEP7 � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 28
13�1 Installation and import of the GSD file � � � � � � � � � � � � � � � � � � � � � � � � � � 28
13�2 Adding an encoder to a STEP7 project � � � � � � � � � � � � � � � � � � � � � � � � � 30
13�3 Parameter setting � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 31

Encoder with Profibus interface
4
1 Preliminary note
1.1 Symbols used
►Instruction
> Reaction, result
[…] Designation of keys, buttons or indications
→Cross-reference
Important note
Non-compliance can result in malfunction or interference�
Information
Supplementary note
1.2 Warning signs used
NOTE
Warning of damage to property�
1.3 Notes on this document
This document applies to encoders of the following type:
RM30xx and RN30xx with Profibus interface
It is part of the device and contains information about the correct handling of the
product�
This document is intended for qualified electricians� These specialists are people
who are qualified by their training and their experience to recognise and to avoid
possible hazards that may be caused during operation of the device�
►Read this document before using the device�
►Keep this document during the service life of the device�
►Observe these operating instructions�
►Adhere to the warning notes�
2 Safety instructions
Non-observance of the instructions, operation which is not in accordance with use
as prescribed below, wrong installation or incorrect handling can affect the safety
of operators and machinery�
The installation and connection must comply with the applicable national and
international standards� Responsibility lies with the person installing the unit� Only
the signals indicated in the technical data or on the device label may be supplied
to the connections or wires�

UK
Encoder with Profibus interface
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3 General information
3.1 1.2 Profibus technology
Profibus is a manufacturer-independent, open fieldbus standard determined by
the international standards EN 50170 and EN 50254�
There are 3 versions: DP, FMS and PA�
ifm encoders support the DP version and are designed for common baud rates
up to 12 Mbaud�
Besides manufacturer-specific functions the devices support the classes 1 and
2 to the encoder profile� This device profile can be ordered from the Profibus
user organisation indicating the order number 3�062�
Here you can also get further information about PROFIBUS (functionality,
manufacturers, products) as well as standards and profiles
→ www�profibus�
com�
4 Functions and features
The encoder converts rotary movements into digital numerical values� Each
revolution and each angular position of the revolutions is provided as a numerical
value� These values allow angular movements to be measured and positions and
number of revolutions to be determined�
Products from ifm electronic gmbh are usually individual components of larger installations� These
applications require tests of the entire installation and do not only depend on the specification of
these components� The notes in this manual apply only to the product from ifm electronic and not to
the entire installation� If the product is used in a non-intended way, this will be at your own risk�

Encoder with Profibus interface
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5 Electrical connection
►Disconnect power�
►Connect the device according to the indications on the type label�
5.1 Connection of the signal and supply cables
Terminal Description
B (left) Signal cable B
Incoming bus cable
A (left) Signal cable A
Incoming bus cable
- 0 V
+ 10���30 V
B (right) Signal cable B
Outgoing bus cable
A (right) Signal cable A
Outgoing bus cable
- 0 V
+ 10���30 V
6 Installation
►Disconnect power�
►Ensure that the machine stands still�
►The drive must not be started during installation�
►Do not hit the shaft; do not use a file or similar tool on the shaft� Risk of
destruction!
This product is a precision measuring device� Therefore it has to be handled with care by trained
staff� The following warnings apply to influences outside the limit values indicated in the product data
sheet�
Damage to the product can be caused by:
●electrostatic discharge while touching the electronics
●too high forces on the shaft
●humidity and chemical liquids (do not connect any cables oriented upwards)
●extreme temperatures
●too high vibrations and shocks
●short circuit or too high an operating voltage
●impact, shock or any other physical forces

UK
Encoder with Profibus interface
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7 Installation
The encoder is connected via the terminal cap� It is connected to the encoder via
a 15-pole D-Sub-connector and can be removed by loosening the 2 screws on the
back of the device� Bus and supply cables are inserted in the cab via cable glands
and connected via screw terminals�
7.1 Settings in the terminal cap
7.1.1 Participant address
The Profibus participant address is set via decimal rotary switches in the terminal
cap� The positional value (x 10 or x 1) is indicated on the switch� Possible
addresses are between 1 and 99; each address must only occur in the system
once�
The device address is read when the voltage supply of the encoder is applied; a
change of address by the master [Set_Slave_Add] is not supported�
Connection and setting of addressing
5
+- BA
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
+-
BA
123
4
1: Supply +UB/ - GND
2: Bus IN
3: Bus OUT
4: Addressing
5: Setting terminating resistor
7.1.2 Bus termination
If the encoder is installed as an end device, the terminal resistor integrated in the
device must be activated� This is done via the slide switch in the terminal cap (5)�

Encoder with Profibus interface
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When the terminal resistor is activated, the next bus (Bus Out) is decoupled�
The bus is only correctly connected if the encoder is installed on the terminal cap� If the encoder has
to be replaced during operation, the use of a separate active bus termination is recommended�
After the address has been set in the hardware and, if applicable, the terminating resistor has been
activated, the encoder can be put into operation�
8 Device configuration
Encoders with Profibus interface can be configured and parameterised according
to the requirements of the user�
In this respect the GSD file of the device is loaded into the projection tool� Various
encoder classes can be selected for the projection� Parameters and functionalities
of the device that can be set depend on the selected encoder class� ifm encoders
of the RM30xx and RN30xx series support all encoder classes described below�
Therefore the functionality is not restricted from the hardware side and is only
determined by the user� ifm encoders do not only provide the encoder classes
"Class 1" and "Class 2" described in the encoder profile but also encoder classes
with manufacturer-specific functions�
When configuring the device, configuration and parameter data are defined by
selecting the encoder class� This data saved in the Profibus master is transferred
once to the encoder when the system starts up (configuration and parameterising
phase – "DDLM_Set_Prm")� It is not possible to change configuration or
parameters during operation�
After the configuration and parameter data has been received, the encoder goes
into normal operation (cyclic data exchange – "DDLM_Data_Exchange mode")
in which, for example, the position value is transferred� The length and format of
the data exchanged are also defined when configuring the device by selecting the
appropriate encoder class�
9 Encoder classes
9.1 Class 1 and Class 2
The encoder classes Class 1 and Class 2 are the versions according to the
encoder profile defined by the encoder working group in the Profibus user
organisation (available from PNO indicating order no� 3�062)�

UK
Encoder with Profibus interface
9
9.2 Parameter setting
The following table gives an overview of the parameters that can be set according
to the encoder profile and of the arrangement in the parameter setting telegram�
Parameters are set using input masks in the projection tool�
Octet (= byte) no. Parameters Bit no. Details
1���8 Profibus standard parameters
9 Direction of rotation 0 → Chapter 9.2.1
Class 2 functionality 1 → Chapter 9.2.2
Commissioning diagnostics 2 → Chapter 9.2.3
Scaling function 3 → Chapter 9.2.4
Reserved 4
Reserved 5
Not used for Class 1 and Class 2 6
7
10���13 Measuring steps / revolution → Chapter 9.2.5
14���17 Total resolution → Chapter 9.2.6
18���25 Reserved (to encoder profile)
26��� Not used for Class 1 and Class 2
Rotational direction
The direction of rotation defines the counting direction of the process actual value
output when the shaft rotates clockwise (CW) or counter-clockwise (CCW)� The
counting direction is defined by bit 0 in octet 9�
Octet 9 bit 0 Direction of rotation when viewing the shaft Direction of
rotation
0 Clockwise (CW) Rising
1 Counter-clockwise (CCW) Rising
9.2.1 Class 2 functionality
Class 2 encoders can be limited to the functionality of Class 1; the possibility of
parameter setting is disabled� To use the function of Class 2 encoders, bit 1 is set
in octet 9�
Octet 9 bit 1 Class 2 functionality
0 Disabled
1 Enabled
9.2.2 Commissioning diagnostics
This function is of no meaning for the ifm encoder�

Encoder with Profibus interface
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9.2.3 Scaling function
The scaling function enables parameter setting of the resolution per revolution and
the selected total resolution� It should always be enabled if you want to use the
functions of Class 2 (or the manufacturer-specific classes)�
Octet 9 bit 3 Scaling function
0 Disabled
1 Enabled
9.2.4 Measuring steps per revolution
This parameter is used to assign a requested number of steps referred to one
revolution to the encoder�
If the value of the parameter exceeds the actual physical basic resolution of the
encoder, the output value no longer proceeds by one step�
For encoders as of the B1 generation a parameter fault is displayed in this case;
the device does not change to the cyclic data transfer�
For high-resolution encoders it may be required to split the value into high word
and low word, depending on the projection tool�
Octet 10 11 12 13
Bit 31���24 23���16 15���8 7���0
Data 231 to 224 223 to 216 215 to 2827to 20
Requested number of measuring steps per revolution
9.2.5 Total resolution
Octet 14 15 16 17
Bit 31���24 23���16 15���8 7���0
Data 231 to 224 223 to 216 215 to 2827to 20
Selected total resolution in measuring steps
This parameter enables the user to adapt the measuring range of the device� The
encoder counts up to the configured total resolution and then it starts again at 0�
Example
Selected: 100 steps per revolution, total resolution 12800, then the encoder starts
again at zero after 128 revolutions and counts again up to 12799�
With many projection tools it may be required to split the value into high word and
low word�

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When the [Total measuring range] parameter is entered, use the following formula:
total resolution < measuring steps per revolution x number of revolutions
(physical)
If this is not observed, the device indicates a parameter fault and does not go into the cyclic data
exchange�
The internal software routine is only effective during operation�
9.3 Data exchange during normal operation
The DDLM_Data_Exchange mode is the normal status during system operation�
On request, the encoder sends current position values to the master� Conversely,
the encoder can also receive cyclic data (e�g� the preset value with Class 2
encoders)�
9.3.1 Transfer of the process actual value
The current position value of the multiturn encoder is transferred as a 32-bit value
(double word) to the master�
Word Word 1 Word 0
Function Process actual value
Bit 31���30 29���16 15���0
0 X X

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9.3.2 Preset function
The preset function enables adaptation of the encoder zero point to the
mechanical zero point of the system�
►Set the encoder actual value to the requested preset value�
> The requested zero point drift is calculated by the device and stored in an
EEPROM (non-volatile) which takes less than 40 ms�
The preset value is activated in the peripheral output double word by setting bit
31 (adopted with rising edge)� Setting is made automatically after transfer of the
scaling parameters, i�e� the preset value refers to the scaled actual value�
Data bits
Bit 4 31 30 29...0
Master → encoder 1 0 Transfer of the requested value
(= preset value)
Encoder → master 0 0 New = requested process actual value is transferred
Master → encoder 0 0 Reset bit 31 - normal mode
Encoder → master 0 0 New = requested process actual value is transferred
Only set the preset while the encoder shaft is at standstill� If the shaft moves
during this time, shifts are possible since runtimes occur via the bus when the
preset value is set�
Note on the singleturn version
The process can be transferred to the singleturn version – here bit 15 is used to
activate the preset value� With high-resolution singleturn encoders (16 bits) no
preset values > 32767 (15 bits) can be set in Class 2 (MSB is used to activate the
preset value)� If this function is requested, one of the manufacturer-specific ifm
classes has to be selected (transfer here also in 32-bit format for the singleturn)�

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10 Profibus encoder profile Class 2
Parameter setting telegram
Octet (= byte) no. Parameters Bit no. Details
1���8 Profibus standard parameter
9 Direction of rotation 0 → Chapter 9.2.1
Class 2 functionality 1 → Chapter 9.2.2
Commissioning diagnostics 2 → Chapter 9.2.3
Scaling function 3 → Chapter 9.2.4
Reserved 4
Reserved 5
Activate manufacturer-specific
parameters (octet 26)
6→ Chapter 10.1.1
Reserved 7
10���13 Measuring steps / revolution
(Reference: octet 26 bits 0 and 1)
→ Chapter 10.1.2
14���17 Total resolution → Chapter 9.2.6
18���25 Reserved
26 Reference to the requested
measuring steps
0
1
→ Chapter 10.1.3
Activate set-up mode 2 → Chapter 10.1.4
Reduced diagnosis 3 → Chapter 10.1.5
Reserved 4
Activate lower software limit switch 5 → Chapter 10.1.6
Activate upper software limit switch 6 → Chapter 10.1.6
Activate parameters as from octet
27
7→ Chapter 10.1.1
27���30 Lower limit switch → Chapter 10.1.6
31���34 Upper limit switch → Chapter 10.1.6
35���38 Physical measuring steps → Chapter 10.1.7
39 Reserved 0
Encoder (singleturn or multiturn) 1 → Chapter 10.1.8
Reserved 2
Reserved 3
Selection of the measuring unit to
provide the value of velocity
4
5
→ Chapter 10.1.9
Reserved 6
Reserved 7

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10.1 Parameters
The manufacturer-specific parameters are described below� The parameters to the
encoder profile (also supported) are described in chapter 9�
10.1.1 Activation of the manufacturer-specic parameters
The manufacturer-specific parameter byte 26 is activated via bit 6 in octet 9�
The manufacturer-specific bytes 27���39 are activated in byte 26�
Octet 9 bit 6 Octet 26
0 Deactivated
1 Activated
Octet 26 bit 7 Octet 27...29
0 Deactivated
1 Activated
10.1.2 Requested measuring steps
The device can be programmed with the [Desired measuring units] parameter so
that any number of measuring steps referred to
– one revolution
– the entire measuring range
– any part of the measuring range
can be implemented�
Octet 10 11 12 13
Bit 31���24 23���16 15���8 7���0
Data 231 to 224 223 to 216 215 to 2827to 20
Required number of measuring steps

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10.1.3 Required resolution
Parameter selection of
– resolution per revolution
– or max� total resolution
– code sequence
– Class 2 functionality
– scaling function
Selection required resolution
Resolution per revolution
The position value is scaled so that it increases by the number of the required
measuring steps during one revolution�
In addition the [Total mesuring range] parameter is evaluated via which the
measuring range can be adapted (→ chapter 9.2.5)
Resolution per max� total resolution
The requested measuring steps entered refer to the total measuring range�
The device provides the configured number of measuring steps via the total
(physical) number of revolutions�

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Resolution per physical measuring steps
The requested number of steps refers to the data entered via the [Physical
impulses] parameter (→ chapter 10.1.7).
This is the numerical value that is read from the coded disc inside the encoder
(e�g� 4096 steps per revolution for the standard 12-bit version)�
This option allows free setting of gearbox factors�
Reference Octet 26 bit 0 Octet 26 bit 1
Per revolution 0 0
Per max� total resolution 1 0
Per physical measuring steps
(= steps indicated in octets 35-38)
0 1
10.1.4 Activate set-up mode
Bit 2 in octet 26 is a switch for the set-up mode�
In this mode other parameters besides the preset value can be transferred to the
encoder�
With activated mode a teach operation can be carried out; the gearbox factor can
be directly determined in the system�
In this mode (green LED flashing) the direction of rotation and scaling set during
projection are ignored and the values saved in the internal EEPROM are used�
The device can be operated permanently in the set-up mode�
Recommendation:
Transfer the parameters determined in the set-up mode and then use the device in
normal mode (which enables a replacement of the device without having to repeat
the teach operation)�
Octet 26 bit 2 Set-up mode
0Off
1 On

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10.1.5 Reduced diagnosis
With older Profibus masters the full number of diagnostic bytes (standard
diagnosis: 57 bytes) may lead to problems� �
With the RM30xx and RN30xx devices it is possible to reduce the number of the
diagnostic bytes provided by the encoder to 16� If the device class "Class 1" is
selected, only 16 diagnostic bytes are provided in general�
Octet 26 bit 3 Diagnostic data length
0 Standard = 57 bytes
1 Reduced = 16 bytes
10.1.6 Software limit switch
2 positions can be programmed� If they are exceeded or not reached, the encoder
sets bit 27 in the 31-bit process actual value to "1"�
Between the two positions the bit is set to "0"� Both limit switch values can be set
to any value via parameter setting but they must not exceed the value of the [Total
measuring range] parameter� The limit switches are activated via bit 5 or 6 in octet
26�
With many projection tools it may be required to split the values into high word and low word�
Octet 27 28 29 30 31 32 33 34
Bit 31���24 23���16 15���8 7���0 31���24 23���16 15���8 7���0
Data 231���224 223���216 215���2827���20231���224 223���216 215���2827���20
Lower limit switch in measuring steps (referred to scaled value)
Octet 26 bit 5 Lower limit switch
0Off
1 On
Octet 26 bit 6 Upper limit switch
0Off
1 On

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10.1.7 Physical measuring steps
Octet 35 36 37 38
Bit 31���24 23���16 15���8 7���0
Data 231���224 223���216 215���2827���20
Physical measuring steps
This parameter is evaluated by the device if the option [Physical impulses] was
selected as reference to the requested measuring steps� By means of the physical
measuring steps a gearbox factor can be freely set� Here it is defined how many
measuring steps (requested measuring steps) are to be provided on a defined
sub-measuring range� This option is useful if "odd" scaling factors are to be
entered�
Example
The encoder is to provide 400 steps over 3 revolutions�
With the reference [Desired measuring units per revolution] this number of steps
cannot be set (the [Desired measuring units] parameter should contain the value
133�333; however only integers can be entered)�
Remedy
The physical measuring steps are selected as reference for the requested
measuring steps�
The number of the physical measuring steps over the requested measuring range
is determined on the basis of the actual (physical) resolution of the device (type
label)� For this absolute encoder with 12-bit standard resolution this would in this
case be
4096 steps/revolution x 3 revolutions = 12288 steps
This value is now entered as [Physical impulses] parameter; the actually required
number of steps of 400 is entered at [Desired measuring units]� The encoder
now provides 400 steps over a measuring range of 12288 physical steps (i�e� 3
revolutions)�
Note: With many projection tools it may be required to split the value into high
word and low word�
10.1.8 Encoder type
The type of encoder (singleturn or multiturn) is defined in bit 1 of octet 39� This
is done automatically when the encoder class is selected� The user only has to
consider this parameter if parameters are set directly in the hexadecimal code�
Octet 39 bit 1 Type
0 Singleturn
1 Multiturn

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10.1.9 Unit of measurement velocity
The unit for the velocity value to be provided (class ifm 2�2) can be set via this
parameter�
Unit Bit 4 Bit 5
Steps / second 0 0
Steps / 100ms 1 0
Steps/10ms 0 1
Revolutions / minute 1 1
10.2 Data exchange during normal operation
The process actual value is in general transferred as a 32-bit word (double word)
with the manufacturer-specific encoder classes ifm 2�1 and ifm 2�2� In addition to
the 25 bits that are provided for the position value 7 other bits are used as status
bits� In the (peripheral) output double word the master sends the preset value and
in addition the control bits to the encoder�
For encoders of this type more than 25-bit absolute position data may be available�
The position values < 25 bits are not supported in the ifm classes; the more
significant bits are overwritten by status bits�
If the ifm classes are to be used with encoders whose physical resolution exceeds
25 bits, the user must ensure that the physical position value is scaled to a (max�)
output value < 33554432 (via parameter setting)� If absolute values > 25 bits are
required, Class 2 has to be selected�
An additional (peripheral) input word of the current velocity value is transferred
with device class ifm 2�2�
Identifica-
tion
F1 hex D0 hex
Encoder →
master
Status + position actual value Velocity
Status + 224 223 - 216 215 - 2827- 20215 - 2827- 20
Master →
encoder
Preset value + control bits
Control + 224 223 - 216 215 - 2827- 20

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The status bits in the input double word have the following meaning
Bit Meaning
28 Rotational direction 0 = increasing clockwise
(seen on the shaft)
1 = increasing counter-clockwise
(seen on the shaft)
27 Software
Limit switch
0 = lower limit switch ≤ actual
value ≤ upper limit switch
1 = actual value > upper limit
switch or actual value < lower
limit switch
26 Operating mode 0 = set-up mode 1 = normal mode
25 Readiness for operation 0 = encoder not ready for
operation
1 = encoder ready for operation
10.3 Set-up mode
If the encoder is switched to the set-up mode via parameter setting, the gearbox
factors can be determined directly in the system via a teach operation�
The set-up mode is signalled by the encoder via a flashing green LED in the
terminal cap and via bit 26 in the input double word (set to 0)�
In the set-up mode the parameters set during projection (direction of rotation,
scaling) are ignored and the values saved in the internal EEPROM are used� If the
direction of rotation and gearbox factor are changed during the set-up mode, the
new values are stored in the EEPROM�
Process during the set-up mode
►Install the device in the system�
►Enable the set-up mode via parameter setting�
►Adapt the direction of rotation (if required)�
►Move the system to the starting position�
►Transmit the start command for the teach operation to the encoder�
►Move the system to the end position�
►Transfer the requested number of steps to the encoder with the "stop teach
operation" command�
►Set the preset value�
►Transfer the values determined during the teach operation to the projection
(parameters)�
►Disable the set-up mode during parameter setting�