POSITAL FRABA User manual

ABSOLUTE ROTARY ENCODER
IXARC EXPLOSION PROOF PROFIBUS-DP
Absolute Rotary Encoder
IXARC EXPLOSION PROOF PROFIBUS-DP
OCM-DPC1B-XXXX-XXXX-XXX
OCE-DPC1B-XXXX-XXXX-XXX
USER MANUAL
User Manual

ABSOLUTE ROTARY ENCODER
IXARC EXPLOSION PROOF PROFIBUS-DP
Page 2 Info Ex OCM/OCE Revision 26.05.2014
1General............................................................4
1.1 Absolute Rotary Encoder...............................4
1.2 Profibus technology.......................................4
2Installation ......................................................5
2.1 Settings in the connection cap.......................5
2.1.1 Station address .......................................5
2.1.2 Bus termination .......................................5
2.2 Connecting bus lines and power supply ........6
2.3 Connecting-up the connection cap with cable
glands..................................................................7
Use only EX d certified cable glands (or blind
plugs, if no cable is attached) which meet
EN/IEC 60079-1 requirements for attaching
cable to the encoder. Cable entry threads are
M20 x 1,5...............................................................7
Connecting the screen.........................................7
2.4 Instructions for mechanical installation and
electrical connection of the angular encoder .......7
3Device Configuration.....................................9
3.1 Overview –Configuration principle................9
3.2 Overview encoder configurations -
functionality........................................................10
3.3 Encoder configurations - data format...........11
4Class 1 and Class 2 profile..........................12
4.1 Parameter settings.......................................12
4.1.1 Code sequence.....................................13
4.1.2 Class 2 functionality ..............................13
4.1.3 Commissioning diagnostics...................13
4.1.4 Scaling function.....................................13
4.1.5 Measuring units per revolution ..............13
4.1.6 Total measuring range ..........................14
4.2 Data exchange in normal operation.............15
4.2.1 Transferring the process value..............15
4.2.2 Preset function ......................................15
5Special versions FRABA 2.1 and 2.2 ..........17
5.1 Parameter....................................................18
5.1.1 Activate manufacturer-specific
parameters .....................................................18
5.1.2 Desired measuring units........................18
5.1.3 Desired Measuring units reference........19
5.1.4 Activate commissioning mode ...............20
5.1.5 Shorter Diagnostics ...............................20
5.1.6 Software-limit switch..............................20
5.1.7 Physical impulses..................................21
5.1.8 Encoder type .........................................22
5.1.9 Velocity time base..................................22
5.2 Data exchange in normal operation .............23
5.3 Commissioning mode...................................24
5.3.1 Setting the counting direction ................24
5.3.2 Teach-In Start........................................25
5.3.3 Teach-In Stop........................................25
5.3.4 Preset value...........................................26
6Diagnostic messages...................................27
6.1 Overview......................................................27
6.2 Supported diagnostic messages..................28
6.2.1 Extended diagnostics header ................28
6.2.2 Memory error.........................................28
6.2.3 Operating status ....................................28
6.2.4 Encoder type .........................................28
6.2.5 Singleturn resolution..............................28
6.2.6 Number of revolutions............................28
6.2.7 Operating time warning..........................28
6.2.8 Profile version........................................28
6.2.9 Software version....................................28
6.2.10 Operating time.....................................28
6.2.11 Zero offset ...........................................29
6.2.12 Programmed resolution .......................29
6.2.13 Programmed total resolution................29
6.2.14 Serial number......................................29
7Configuring with STEP 7..............................30
7.1 Installing the GSD file...................................30
7.2 Configuring the encoder...............................31
7.3 Selecting the encoder version......................32
7.4 Setting the parameters.................................33
7.5 Further encoder configurations....................37

ABSOLUTE ROTARY ENCODER
IXARC EXPLOSION PROOF PROFIBUS-DP
Revision 26.05.2014 Info Ex OCM/OCE Page 3
7.5.1 Version FRABA 2.0 Multiturn.................37
7.5.2 Version FRABA 1.1 Multiturn.................37
7.5.3 Version FRABA 1.0 Multiturn.................37
7.5.4 Class 2 Multiturn ‚DX-Version’...............37
7.6 FAQ absolute encoder Profibus...................38
7.7 Definitions....................................................39
8Index..............................................................41
Imprint
FRABA B.V.
Gebouw A, Unit 27,
Jan Campertstraat 5,
6416 SG Heerlen
Netherlands
Telephone ++49/(0) 221/ 96213-0
Fax ++49/ (0) 221/ 96213-20
Internet http://www.posital.com
E-mail [email protected]
Copyright
The company Fraba B.V. claims copyright on this
documentation. It is not allowed to modify, to
extend, to hand over to a third party and/or to copy
this documentation without written approval by the
company FRABA B.V.
Specifications are subject to change without
notice
Technical specifications, which are described in
this manual, are subject to change due to our
permanent strive to improve our products.
Publication: Mai, 2014
Version: 1.2
Author: Wojciech Pająk
Certification -
-I M2 Ex db Mb OCM Mining
-II 2 G/D Ex db IIC T5 Gb
-II 2 G/D Ex tb IIIC T100°C Db IP 64/65/66/67
-Ambient temperatures - 40°C to 70°C
-
Certification Number OCM
TUV 13 ATEX 113112 X
IECEx TUN 12.0044X
Certification Number OCE
TUV 13 ATEX 113110X
IECEx TUN 12.0043X
-I EC 60079-0 Explosive atmospheres - Part 0:Equipment –General requirements
-IEC 60079-1 Explosive atmospheres - Part 1: Equipment protection by flameproof enclosures "d"
-IEC 60079-31 Electrical apparatus for use in the presence of combustible dust - Part 1: Protection by
enclosures "tD", IP6X
-IEC 60529-1991 +A1 Degree of protection provided by enclosure (IP Code)

ABSOLUTE ROTARY ENCODER
IXARC EXPLOSION PROOF PROFIBUS-DP
Page 4 Info Ex OCM/OCE Revision 26.05.2014
1 General
This manual describes installation and
configuration of the Absolute Rotary Encoder with
Profibus DP interface. The device meets the
requirements of a Profibus Slave according to the
PROFIBUS standard. It is certified by the “Profibus
Nutzerorganisation” in Germany.
1.1 Absolute Rotary Encoder
Basic principle of the absolute measurement is the
optical scanning of a transparent disk with code
print. The code disk is connected to the shaft that
is to be measured. By evaluating the code and two
additional incremental signals the absolute position
of the shaft can be determined with a resolution of
up to 65536 steps per revolution (16 bits).
So-called Multiturn-devices use reduction gears
and further code disks to determine the absolute
shaft position over up to 16384 revolutions (14
bits).
The position value is calculated in an integrated
microprocessor and transmitted over the Profibus.
Further information about the basic function
principle of Absolute Rotary Encoders and Profibus
networks can be found on our homepage
www.posital.com .
1.2 Profibus technology
PROFIBUS is an international, open, non-
proprietary fieldbus standard which is defined in
the international standards EN 50170 and EN
50254. There are three different versions: Profibus
DP, Profibus-FMS and Profibus-PA. FRABA
absolute encoders are designed for the DP
version. They support all usual baud rates up to 12
MBaud.
Besides manufacturer-specific functions, the
devices support the classes 1 and 2 according to
the Profile for Absolute Encoders (this device
profile can be ordered under part number 3.062
from the “Profibus Nutzeroganisation”). Further
information about profibus (functionality,
manufacturer, products), standards and device
profiles are available from the PNO:
Profibus Nutzerorganisation (PNO)
Haid-und-Neu-Straße 7
D-76131 Karlsruhe
Tel.:++49 (0) 721 / 96 58 590
Fax:++49 (0) 721 / 96 58 589
www.profibus.com

ABSOLUTE ROTARY ENCODER
IXARC EXPLOSION PROOF PROFIBUS-DP
Revision 26.05.2014 Info Ex OCM/OCE Page 5
2 Installation
The Absolute Encoder is connected with a
connection cap. This cap is connected to the
encoder with a 15-pin-D-Sub connector and can be
removed by loosening two screws on the backside
of the encoder. Bus lines and power supply are led
into the cap via cable glands and connected to
terminal blocks.
2.1 Settings in the connection cap
2.1.1 Station address
The station (node) address is set by using the
rotary switches in the cap. The values (x 10 or x 1)
for the switches are marked at the switch. Possible
addresses are between 0 and 99. Each address
can only be used once in the network. The station
address is read in when switching on the power
supply. An address change by the Master
(“Set_Slave_Add“) is not supported.
2.1.2 Bus termination
If the encoder is connected at the end or beginning
of the bus line the termination resistor must be
switched on (slide switch in position “ON”).
ON
R
ON
R
device X last device
Note
The outgoing bus line is disconnected if the
resistor is switched on!
The bus is only correctly terminated when the
encoder is connected to the connection cap. If the
encoder must be changed during operation, a
separate active bus termination should be used.

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2.2 Connecting bus lines and power supply
The power supply has to be connected once (no
matter which clamps). If the terminating resistor
is switched on, the outgoing bus lines are
disconnected.
Clamp
Description
B (left)
Bus line B (Bus in)
A (left)
Bus line A (Bus in)
−
0 V
+
10 –30 V
B (right)
Bus line B (Bus out)
A (right)
Bus line A (Bus out)
−
0 V
+
10 –30 V

ABSOLUTE ROTARY ENCODER
IXARC EXPLOSION PROOF PROFIBUS-DP
Revision 26.05.2014 Info Ex OCM/OCE Page 7
2.3 Connecting-up the connection cap
with cable glands
Use only EX d certified cable glands (or blind
plugs, if no cable is attached) which meet
EN/IEC 60079-1 requirements for attaching
cable to the encoder. Cable entry threads are
M20 x 1,5.
Use only shielded cable. Be aware of National
Wiring Standards for ATEX environments. For
ambient temperatures below -10o C and above
+60 C use field wiring suitable for minimum and
maximum ambient temperatures.
Installation requirments
Installation of the encoder must be completed
by a skilled technician or engineer. Failure to
comply with the instructions below will render
the ATEX/IECEx certifications INVALID. The
encoder may not be modified by the
customer.
Insure that power is off.
Connect to earth prior to proceeding. Observe
precautions for handling ESD (Electro Static
Discharge) sensitive devices.
Connecting the screen
To achieve the highest possible noise immunity
shielded cables should be used for data
transmission. The shield should be connected to
ground on both ends of the cable. In certain cases,
a compensation current might flow over the shield.
Therefore a potential compensation cable is
recommended.
2.4 Instructions for mechanical installation and electrical connection of the angular encoder
The following points should be observed:
Do not drop the angular encoder or subject it
to excessive vibration. The encoder is a
precision device.
Do not open the angular encoder housing
(this does not mean that you cannot remove
the connection cap). If the device is opened
and closed again, it can be damaged and dirt
may enter the unit.
The angular encoder shaft must be
connected to the shaft to be measured
through a suitable coupling (full shaft
version). This coupling is used to dampen
vibrations and imbalance on the encoder
shaft and to avoid inadmissible high forces.
Suitable couplings are available from FRABA.
Although FRABA absolute encoders are
rugged, when used in tough ambient
conditions, they should be protected against
damage using suitable protective measures.

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The encoder should not be used as handles
or steps.
Only qualified personnel may commission
and operate these devices. These are
personnel who are authorized to commission,
ground and tag devices, systems and circuits
according to the current state of safety
technology.
It is not permissible to make any electrical
changes to the encoder.
Route the connecting cable to the angular
encoder at a considerable distance or
completely separated from power cables with
their associated noise. Completely shielded
cables must be used for reliable data transfer
and good grounding must be provided.
Cabling, establishing and interrupting
electrical connections may only be carried-out
when the equipment is in a no-voltage
condition. Short-circuits, voltage spikes etc.
can result in erroneous functions and
uncontrolled statuses which can even include
severe personnel injury and material damage.
Before powering-up the system, check all of
the electrical connections. Connections,
which are not correct, can cause the system
to function incorrectly. Fault connections can
result in severe personnel injury and material
damage.

ABSOLUTE ROTARY ENCODER
IXARC EXPLOSION PROOF PROFIBUS-DP
Revision 26.05.2014 Info Ex OCM/OCE Page 9
3 Device Configuration
The Absolute Encoder with Profibus-Interface can
be programmed according to the needs of the
user. The GSD-file has to be installed in the used
software tool. The user has the possibility to
choose different encoder configurations.
Parameters and functionality depend on the
selected encoder configuration. FRABA-Absolute
Encoders Type „OCD-DPC1B-XXXX-XXXX-0CC“
support all configurations described in the
following, i.e. there is no functionality limitation due
to the hardware. Additionally to the configurations
„Class 1“ and „Class 2” (according to the Profile for
Encoders) the FRABA Encoder offers
configurations with manufacturer-specific functions.
By choosing a certain encoder configuration
parameter and configuration data are determined.
These data are stored in the profibus master. They
are transmitted to the slave (encoder) when the
profibus network is starting up („DDLM_Set_Prm“).
It is not possible to change parameters or
configuration during the normal operation of the
device (exception: “Commissioning Mode”, see
chapter 5.3).
After receiving configuration and parameter data
the absolute encoder enters the normal operating
mode (cyclic data transmission –
„DDLM_Data_Exchange“). In this mode the
process values (e.g. the position value) are
transmitted. Data length and format are
determined by the user when selecting a certain
encoder configuration.
3.1 Overview –Configuration principle
GSD-File
Software Tool database
PLC
Choice of encoder configuration
Parameter settings
Parameter („DDLM_Set_Prm“)
Once at Start-Up
Cyclic Data Transmission
(e.g. position value)

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3.2 Overview encoder configurations - functionality
Designation
Cyclic communication
Programmable
parameters
Additional functions
Class 1
Singleturn
Position value - 16 bit Input
Code sequence
-
Class 1
Multiturn
Position value - 32 bit Input
Code sequence
-
Class 2
Singleturn
Position value - 16 bit Input
Preset value - 16 bit Output
Code sequence
Scaling factor
Preset function
Class 2
Multiturn
Position value - 32 bit Input
Preset value - 32 bit Output
Code sequence
Scaling factor
Preset function
FRABA 2.1
Singleturn
Position value (32 bit Input)
Preset value / Teach-In
(32 bit Output)
Code sequence
Scaling factor
Shorter Diagnostics
Limit switches
Preset function
Commissioning mode
FRABA 2.1
Multiturn
Position value (32 bit Input)
Preset value / Teach-In
(32 bit Output)
Code sequence
Scaling factor
Shorter Diagnostics
Limit switches
Preset function
Commissioning mode
FRABA 2.2
Singleturn
Position value (32 bit Input)
Preset value / Teach-In
(32 bit Output)
Velocity
(16 bit Input)
- Code sequence
- Scaling factor
- Shorter Diagnostics
- Limit switches
- Velocity time base
Preset function
Commissioning mode
Velocity Output
FRABA 2.2
Multiturn
Position value (32 bit Input)
Preset value / Teach-In
(32 bit Output)
Velocity
(16 bit Input)
- Code sequence
- Scaling factor
- Shorter Diagnostics
- Limit switches
- Velocity time base
Preset function
Commissioning mode
Velocity Output

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Revision 26.05.2014 Info Ex OCM/OCE Page 11
3.3 Encoder configurations - data format
Designation
Configuration
Input words
(Encoder ->
Master)
Output words
(Master ->
Encoder)
Description
Hex
Dec.
Chapter
Page
Class 1 Singleturn
(According to Profile)
D0
208
1
0
4
12
Class 1 Multiturn
(According to Profile)
D1
209
2
0
Class 2 Singleturn
(According to Profile)
F0
240
1
1
Class 2 Multiturn
(According to Profile)
F1
241
2
2
FRABA 2.1 Singleturn
F1
241
2
2
5
17
FRABA 2.1 Multiturn
F1
241
2
2
FRABA 2.2 Singleturn
F1
D0
241
208
2
1
2
FRABA 2.2 Multiturn
F1
D0
241
208
2
1
2
The following encoder configurations are still supported for reasons of downward compatibility, but
should not be used for new projects (description: see Appendix):
Class 2 Multiturn
„DX-Version“
F1
241
2
2
7.5.4
37
FRABA 1.0 Multiturn
D3
211
4
0
7.5.3
37
FRABA 1.1 Multiturn
D3
E1
211
225
4
0
0
2
7.5.2
37
FRABA 2.0 Multiturn
F1
D0
241
208
2
1
2
7.5.1
37

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4 Class 1 and Class 2 profile
The encoder versions Class 1 and Class 2 are
defined by the working group encoder in the
„Profibus Nutzerorganisation“ in the “Profile for
Encoders” (available from the PNO, Order No.
3.062).
4.1 Parameter settings
The following table contains an overview of the
parameters according to the Profile for Encoders
and the structure of the parameter telegram.
(Usually it is not necessary for the user to know the
details of the structure –the parameters are set in
user-friendly forms in the operator software tool.)
Octet (= byte) No.
Parameter
Bit Nr.
Details
1 ... 8
Profibus Standard Parameters
9
Code sequence
0
Class 2 functionality
1
Section 4.1.2, Page 13
Commissioning Diagnostics
2
Section 4.1.3, Page 13
Scaling function
3
Section 4.1.4, Page 13
Reserved
4
Reserved
5
Not used for Class 1 and Class 2
6
7
10
...
13
Measuring units per revolution
Section 4.1.5, Page 13
14
...
17
Total measuring range
Section 4.1.6, Page 14
18
...
25
Reserved (Profile)
26
...
Not used for Class 1 and Class 2
(Refer to versions FRABA 2.1 und 2.2)

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Revision 26.05.2014 Info Ex OCM/OCE Page 13
4.1.1 Code sequence
The parameter „code sequence“ defines the
counting direction of the position value. The code
increases when the shaft is rotating clockwise
(CW) or counter-clockwise (CCW) (view onto the
shaft). The code sequence is defined in bit 0 of
octet 9:
Octet 9 Bit 0
Direction of rotation when viewing the shaft
Code
0
Clockwise (CW)
Increasing
1
Counter-clockwise (CCW)
Increasing
In Class 1 this is the only parameter that can be set.
4.1.2 Class 2 functionality
Using this switch Class 2 encoders can be
restricted to the functionality of Class 1, i.e. the
scaling parameters are disabled. To use the class
2 functionalities bit 1 in octet 9 has to be set.
4.1.3 Commissioning diagnostics
This function has no significance for the FRABA
encoder.
4.1.4 Scaling function
The parameter „scaling function“ enables the
scaling parameters „resolution per revolution“ and
„total resolution“. This switch should always be
activated if functions of class 2 (or even higher
classes FRABA 2.1 and FRABA 2.2) are to be
used.
4.1.5 Measuring units per revolution
The parameter „measuring units per revolution“ is
used to program a desired number of steps over
one revolution. If the value exceeds the basic
(physical) resolution of the encoder, the output
code is no longer in single steps. Starting with
generation “B1” the encoder indicates a parameter
error (LED) and it will not enter the data exchange
mode.
With high resolution encoders it may be necessary
to divide the value into high and low word
(depending on the software tool), refer to page 34.
Octet
10
11
12
13
Bit
31 - 24
23 - 16
15 - 8
7 –0
Data
231 to 224
223 to 216
215 to 28
27to 20
Desired measuring units per revolution
Octet 9 Bit 1
Class 2 functionality
0
Switched off
1
Switched on
Octet 9 Bit 3
Scaling function
0
Switched off
1
Switched on

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4.1.6 Total measuring range
The parameter „total measuring range“ is used to
adapt the measuring range of the encoder to the
real measuring range of the application. The
encoder counts up until the position value has
reached the programmed total resolution and
starts with 0 again.
Example: 100 steps are programmed for each
revolution (parameter „measuring units per
revolution“) and the total resolution is set to 12800.
Then the encoder counts up to 11799, starts with
“0” again after 128 revolutions, counts up to 11799,
and so on.
Note: With many software tools it is necessary to
divide the value into high and low word, refer to
page 34.
When choosing the total resolution the following
rule has to be observed:
If “steps per revolution” are set to “n” the parameter total resolution must not cause periods longer than
the maximum (physical) number of revolutions (see type label), i.e. that the programmed total resolution
of a 4096 revolution multiturn encoder must be less than 4096 x the programmed number of steps per
revolution (the programmed total resolution of a 16384 revolution multiturn encoder must be less than
16384 x the programmed number of steps per revolution):
Total resolution < measuring units per revolution x real number of revolutions (physical)
If this rule is disregarded the encoder will indicate a parameter error and it will not enter the data
exchange mode.
With older versions a further rule had to be
observed (see below). If this rule was ignored,
problems occurred when using the device in
endless operation (when crossing the physical
zero point). With new devices (software version
3 Generation A1 or higher) this problem is
solved by an internal software routine. For that
reason the 2nd rule can be ignored if a new
device is used.
Note: The internal software routine only works if the
encoder is in operation. If it is necessary to turn the
encoder shaft more than 1024 revolutions without
power supply this can lead to problems (the internal
routine will not work without power supply). In this
case the following rule should be observed even with
new devices:
The period, i.e. “Total resolution” / “measuring units” per revolution must be an integer and it must fit an
integer number of times (integer multiple) into 4096. So the following equation must apply:
(4096 x measuring units per revolution) / Total resolution = integer
For multiturn devices with 16384 revolution the rule
is as follows (if it is necessary to turn the encoder
shaft more than 4096 revolutions without power
supply):
Octet
14
15
16
17
Bit
31 –24
23 –16
15 - 8
7 - 0
Data
231 to 224
223 to 216
215 to 28
27to 20
Programmed total measuring range in steps

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The period, i.e. “Total resolution” / “measuring units” per revolution must be an integer and it must fit an
integer number of times (integer multiple) into 16384. So the following equation must apply:
(16384 x measuring units per revolution) / Total resolution = integer
4.2 Data exchange in normal operation
The „DDLM_Data_Exchange mode“ is the normal
operation mode of the device. On request the
encoder transfers the current (position) value to
the master. The encoder can also receive data
from the master (e.g. the preset value in the class
2 configuration).
4.2.1 Transferring the process value
The multiturn encoder transmits the current
position value as a 32-bit-value (double word) to
the master.
Word
Word 1
Word 0
Function
Process value
Bit
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0
0
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
The Singleturn encoder uses a 16-bit-value (word)
for data transmission.
4.2.2 Preset function
Using the preset function it is possible to adapt he
encoder zero point to the zero point of the
application. When using this function the current
encoder position value is set to the desired preset
value. The integrated microcontroller calculates the
internal zero point shift. It is stored non-volatile in
an EEPROM (takes less than 40 ms).
The preset value is activated if bit 31 in the
(peripheral) output double word is set to 1 (rising
edge). As the preset function is used after
receiving the scaling parameters the preset value
refers to the scaled position value.

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Data bits
Bit
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Master →OCD
1
0
Transfer of the required position value (= preset value)
OCD →Master
0
0
New = required position value is transferred
Master →OCD
0
0
Reset bit 31 –normal mode
OCD →Master
0
0
New = required position value is transferred
If high precision is required the preset function
should only be executed if the encoder shaft is not
moving. If the shaft moves quickly during the
preset procedure, this can result in offsets
(because of bus delay times).
Note for Singleturn devices
The procedure is similar with the singleturn-
version: Here Bit 15 is used to activate the preset
value. With high resolution singleturn encoders (16
Bit) it is not possible to set preset values > 32767
(15 bit), as the MSB is used to activate the preset.
If this functionality is needed the user has to
choose one of the manufacturer specific FRABA-
encoder versions (in these classes the singleturn
position is transmitted as 32-bit-value).

ABSOLUTE ROTARY ENCODER
IXARC EXPLOSION PROOF PROFIBUS-DP
Revision 26.05.2014 Info Ex OCM/OCE Page 17
5 Special versions FRABA 2.1 and 2.2
The manufacturer-specific encoder configurations
FRABA 2.1 and FRABA 2.2 offer (in addition to the
functions according to the Profile for Encoders)
features such as commissioning mode, velocity
output and software limit switches.
The following table gives an overview of the used
parameters and the structure of the parameter
telegram.
Usually it is not necessary to know these details as
the parameters are set with user-friendly software
tools.
Octet (byte)
No.
Parameter
Bit
No.
Details
Section
Page
1 .. 8
Profibus Standard Parameters
9
Code sequence
0
4.1.1
13
Class 2 functionality
1
4.1.2
13
Commissioning Diagnostics
2
4.1.3
13
Scaling function
3
4.1.4
13
Reserved
4
Reserved
5
Activate manufacturer-specific parameters (octet 26)
6
5.1.1
18
Reserved
7
10 .. 13
Desired measuring units (refer to: octet 26 bit 0 and 1)
5.1.2
18
14 .. 17
Total measuring range
4.1.6
14
18 .. 25
Reserved
26
Reference for the desired measuring steps
0
5.1.3
19
1
Activate commissioning mode
2
5.1.4
20
Shorter Diagnostics
3
5.1.5
20
Reserved
4
Activate lower limit-switch
5
5.1.6
20
Activate upper limit-switch
6
5.1.6
20
Activate octets 27-39
7
5.1.1
18
27 .. 30
Lower limit switch
5.1.6
20
31 .. 34
Upper limit switch
5.1.6
20
35 .. 38
Physical impulses
5.1.7
21
39
Reserved
0
Encoder type (Single-/Multiturn)
1
5.1.8
22
Reserved
2
Reserved
3
Time base velocity
4
5.1.9
22
5
Reserved
6
Reserved
7

ABSOLUTE ROTARY ENCODER
IXARC EXPLOSION PROOF PROFIBUS-DP
Page 18 Info Ex OCM/OCE Revision 26.05.2014
5.1 Parameter
In the following the manufacturer specific
parameters are described in detail. The parameters according to the Profile for Encoders are supported too, description: see chapter 4.
5.1.1 Activate manufacturer-specific parameters
The manufacturer-specific parameter byte 26 is
activated with bit 6 in octet 9.
Bit 7 in octet 26 activates further parameter bytes
(27-39).
Usually this happens automatically if the encoder
versions FRABA 2.1 or FRABA 2.2 are selected. It
is only important for the user to observe this if the
parameters are entered “manually” (directly using
hex-code).
Octet 9 Bit 6
Octet 26
0
Deactivated
1
Activated
Octet 26 Bit 7
Octet 27 –39
0
Deactivated
1
Activated
5.1.2 Desired measuring units
The parameter „desired measuring units“ is used to
program any required number of steps over 1 revolution, over the whole measuring range or over a part of the measuring range.
The reference for the desired measuring units is
specified with the parameter „Desired measuring
units reference“ (cp. 5.1.3). If “per revolution” is
selected the measuring range can be adapted with
the parameter “total measuring range”. Please
observe the rules in section 4.1.6.
Note: With many software tools it is necessary to
divide the value into high and low word, refer to
page 34.
Octet
10
11
12
13
Bit
31 - 24
23 - 16
15 - 8
7 –0
Data
231 to 224
223 to 216
215 to 28
27to 20
Desired measuring units

ABSOLUTE ROTARY ENCODER
IXARC EXPLOSION PROOF PROFIBUS-DP
Revision 26.05.2014 Info Ex OCM/OCE Page 19
5.1.3 Desired Measuring units reference
With this parameter the reference for the desired
measuring units (cp. 5.1.2) is determined, either
- per revolution
- per maximum total resolution
- per number of physical impulses
Desired measuring units per revolution
In this case the position value increases by the
programmed number of steps (desired measuring
units) over one revolution.
Additionally the parameter “total resolution” is used
to achieve an adaptation of the measuring range
(cp. 4.1.6).
Desired measuring units per maximum total
measuring range
The parameter „desired measuring units“ refers to
the complete measuring range of the encoder, i.e.
the encoder gives out the programmed number of
measuring units over the whole measuring range
(4096 revolutions with the multi turn encoder).
Desired measuring units per physical impulses
The desired measuring units refer to the physical
impulses entered in octets 35-39 (cp.5.1.7).
Physical impulses means: The real value that is
read internally from the code disc (e.g. 4096 steps
per revolution with a standard 12-bit-encoder).
With that option it is possible to set gearing factors
freely.
Reference
Octet 26 Bit 0
Octet 26 Bit 1
Per revolution
0
0
Per maximum total measuring range
1
0
Per physical impulses
(= steps specified in octets 35-38)
0
1

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Page 20 Info Ex OCM/OCE Revision 26.05.2014
5.1.4 Activate commissioning mode
Bit 2 in octet 26 activates the commissioning
mode. This is a special mode with the option to set
further parameters in the data-exchange –mode
(additional to the preset value). In the
commissioning mode a „Teach-In“ can be carried
out, i.e. the gearing factor can be determined
directly in the machine. In this special mode
(indicated by the flashing green LED) the
parameters set in the system configuration are
ignored by the encoder. It uses parameters stored
in an internal EEPROM instead.
The commissioning mode can be used durably, but
it is recommended to transfer the parameters
determined with the Teach-In into the system
configuration. Then the encoder should be used in
“normal” operation mode – so it is possible to
exchange the device without a new Teach-In.
A detailed description of the commissioning mode
can be found in section 5.3.
Octet 26 Bit 2
Commissioning mode
0
Switched off
1
Switched on
5.1.5 Shorter Diagnostics
Some Profibus masters, especially older ones,
have problems with the full diagnostic data length
(57 bytes). The FRABA encoder offers the option
to reduce the diagnostic data length to 16 bytes. If
Class 1 is used the standard diagnostic data length
is 16 bytes.
Octet 26 Bit 3
Diagnostics
0
Standard = 57 bytes
1
Reduced = 16 bytes
5.1.6 Software-limit switch
Two positions can be programmed. If the position
value falls below the lower limit switch or exceeds
the higher limit switch, bit 27 in the 32-Bit-process-
value is set to 1. Between these limit switches bit
27 is set to 0. The limit switches can be set to any
value, but the parameter “total measuring range”
must not be exceeded. The limit switches are
activated with bits 5 and 6 in octet 26.
Note: With many software tools it is necessary to
divide the values into high and low word, refer to
page 34.
Octet
27
28
29
30
Bit
31 - 24
23 - 16
15 –8
7 - 0
Data
231 to 224
223 to 216
215 to 28
27to 20
Lower limit switch (in measuring steps, related to the scaled value)
Octet
31
32
33
34
Bit
31 - 24
23 - 16
15 –8
7 - 0
Data
231 to 224
223 to 216
215 to 28
27to 20