turck IO-LINK MASTER User manual

IO-LINK
MASTER -
User Manual

All brand and product names are trademarks or registered trade marks of the owner
concerned.
Edition 11/2008
©Hans Turck GmbH, Muelheim an der Ruhr
All rights reserved, including those of the translation.
No part of this manual may be reproduced in any form (printed, photocopy, microfilm or any
other process) or processed, duplicated or distributed by means of electronic systems
without written permission of Hans Turck GmbH & Co. KG, Muelheim an der Ruhr.
Subject to alterations without notice

Warning!
Before commencing the installation
Disconnect the power supply of the device.
Ensure that devices cannot be accidentally restarted.
Verify isolation from the supply.
Earth and short circuit.
Cover or enclose neighboring units that are live.
Follow the engineering instructions of the device concerned.
Only suitably qualified personnel in accordance with EN 50 110-1/-2 (VDE 0 105 Part 100)
may work on this device/system.
Before installation and before touching the device ensure that you are free of electrostatic
charge.
The functional earth (FE) must be connected to the protective earth (PE) or to the potential
equalization. The system installer is responsible for implementing this connection.
Connecting cables and signal lines should be installed so that inductive or capacitive inter-
ference do not impair the automation functions.
Install automation devices and related operating elements in such a way that they are well
protected against unintentional operation.
Suitable safety hardware and software measures should be implemented for the I/O inter-
face so that a line or wire breakage on the signal side does not result in undefined states
in the automation devices.
Ensure a reliable electrical isolation of the low voltage for the 24 volt supply. Only use
power supply units complying with IEC 60 364-4-41 (VDE 0 100 Part 410) or HD 384.4.41
S2.
Deviations of the mains voltage from the rated value must not exceed the tolerance limits
given in the specifications, otherwise this may cause malfunction and dangerous opera-
tion.
Emergency stop devices complying with IEC/EN 60 204-1 must be effective in all oper-
ating modes of the automation devices. Unlatching the emergency-stop devices must not
cause restart.
Devices that are designed for mounting in housings or control cabinets must only be oper-
ated and controlled after they have been installed with the housing closed. Desktop or
portable units must only be operated and controlled in enclosed housings.
Measures should be taken to ensure the proper restart of programs interrupted after a
voltage dip or failure. This should not cause dangerous operating states even for a short
time. If necessary, emergency-stop devices should be implemented.
Wherever faults in the automation system may cause damage to persons or property,
external measures must be implemented to ensure a safe operating state in the event of a
fault or malfunction (for example, by means of separate limit switches, mechanical inter-
locks etc.).
The electrical installation must be carried out in accordance with the relevant regulations
(e. g. with regard to cable cross sections, fuses, PE).
All work relating to transport, installation, commissioning and maintenance must only be
carried out by qualified personnel. (IEC 60 364 and HD 384 and national work safety regu-
lations).
All shrouds and doors must be kept closed during operation.

D301171 - IO-Link master 1108 i
Table of Contents
About this Manual
Documentation Concept .................................................................................................. 0-2
Description of Symbols Used ........................................................................................... 0-3
Overview .......................................................................................................................... 0-4
Prescribed Use ...............................................................................................................................0-4
Notes Concerning Planning /Installation of this Product................................................................0-4
1PROFIBUS-DP
System overview .............................................................................................................. 1-2
Master/Slave system ......................................................................................................................1-2
System configuration and device types .........................................................................................1-2
Topology.........................................................................................................................................1-3
Maximum system extension ...........................................................................................................1-3
Transmission rate/Cycle times .......................................................................................................1-4
Transmission cables .......................................................................................................................1-4
Diagnostic functions .......................................................................................................................1-5
Sync and Freeze Mode...................................................................................................................1-6
System performance ......................................................................................................................1-6
GSD files .........................................................................................................................................1-8
Short Description of PROFIBUS-DPV1 ............................................................................. 1-9
General ...........................................................................................................................................1-9
Acyclic data transfer .......................................................................................................................1-9
DPV1-functions...............................................................................................................................1-9
DPM1 versus DPM2 .......................................................................................................................1-9
Addressing the data using acyclic services..................................................................................1-10
2IO-Link
IO-Link - the fieldbus-independent communication interface ......................................... 2-2
General technical information.........................................................................................................2-2
Transmission media........................................................................................................................2-3
Fieldbus integration ........................................................................................................................2-4
IO-Link and FDT/DTM.....................................................................................................................2-4
3 Technical features
Function ........................................................................................................................... 3-2
Technical data..................................................................................................................3-3
Connection possibilities................................................................................................... 3-7
Fieldbus connection .......................................................................................................................3-7
Supply voltage ................................................................................................................................3-7
M12-connector for IO-Link .............................................................................................................3-7

D301171 - IO-Link master 1108ii
Address setting ................................................................................................................ 3-8
Process image.................................................................................................................. 3-9
Process input data..........................................................................................................................3-9
Status displays and diagnostic messages...................................................................... 3-10
Status displays via LEDs ..............................................................................................................3-10
Diagnostic messages/ status messages via software..................................................................3-12
GSD-file.......................................................................................................................... 3-15
Entries in the GSD-file ..................................................................................................................3-15
Parameterization............................................................................................................ 3-19
Parameters of the IOLMM (slot 1, IO-Link master module) .........................................................3-19
Parameters of slots 2 to 5, IO-Link device module (IOLDM) ........................................................3-21
IO-Link sensors from TURCK .......................................................................................................3-22
Description of user data for acyclic services ................................................................ 3-24
Gateway Application Instance, Slot 0...........................................................................................3-24
Module Application Instance, Slot 1.............................................................................................3-24
4 Connection to a Siemens Step 7 - usage of the TURCK-example program
Introduction ..................................................................................................................... 4-2
Electronic Device Data Sheets (GSD)............................................................................... 4-3
Application example with Siemens PLC and FB 102 (IO-Link CALL) ................................ 4-4
Application example - prerequisites ...............................................................................................4-4
The example project .......................................................................................................................4-4
5 Acyclic data exchange via PROFIBUS-DP C2-master and TURCK IO-Link DTM
Communication via DTM with C2-master......................................................................... 5-2
Used hardware ...............................................................................................................................5-2
Used software.................................................................................................................................5-2
Hardware-configuration C2-master................................................................................................5-2
Configuration of the CommDTM in PACTware™ ...........................................................................5-4
Configuration of the IO-Link master ...............................................................................................5-5
6 Guidelines for electrical installation
General Notes .................................................................................................................. 6-2
General ...........................................................................................................................................6-2
Cable routing ..................................................................................................................................6-2
Lightning protection........................................................................................................................6-3
Transmission cables .......................................................................................................................6-3
Potential relationships ..................................................................................................... 6-4

D301171 - IO-Link master 1108 iii
Electromagnetic compatibility (EMC) ............................................................................... 6-5
Ensuring electromagnetic compatibility .........................................................................................6-5
Grounding of inactive metal components ......................................................................................6-5
PE connection.................................................................................................................................6-5
Shielding of cables .........................................................................................................................6-6
Potential compensation ..................................................................................................................6-7
Switching inductive loads...............................................................................................................6-7
7Index

D301171 - IO-Link master 1108iv

D301171 - IO-Link master 1108 0-1
About this Manual
Documentation Concept ......................................................................................................2
Description of Symbols Used ...............................................................................................3
Overview ..............................................................................................................................4
Prescribed Use .................................................................................................................................. 4
Notes Concerning Planning /Installation of this Product................................................................... 4

About this Manual
D301171 - IO-Link master 11080-2
Documentation Concept
This manual contains all information about the TURCK IO-Link master SDPX-IOL4-0001.
The following chapters contain a short IO-Link description, exact information about function
and structure of the IO-Link master as well as information concerning the connection to auto-
mation devices and the different possibilities of parameterization for the master and the
connected IO-Link sensors.

D301171 - IO-Link master 1108 0-3
Description of Symbols Used
Description of Symbols Used
Warning
This sign can be found next to all notes that indicate a source of hazards. This can
refer to danger to personnel or damage to the system (hardware and software) and
to the facility.
This sign means for the operator: work with extreme caution.
Attention
This sign can be found next to all notes that indicate a potential hazard.
This can refer to possible danger to personnel and damages to the system (hard-
ware and software) and to the facility.
Note
This sign can be found next to all general notes that supply important information
about one or more operating steps.
These specific notes are intended to make operation easier and avoid unnecessary
work due to incorrect operation.

About this Manual
D301171 - IO-Link master 11080-4
Overview
This manual includes all information necessary for the prescribed use of SDPX-IOL4-0001.
It has been specially conceived for personnel with the necessary qualifications.
Prescribed Use
Appropriate transport, storage, deployment and mounting as well as careful operating and
thorough maintenance guarantee the trouble-free and safe operation of these devices.
Notes Concerning Planning /Installation of this Product
Attention
Please read this section carefully. Safety aspects cannot be left to chance when
dealing with electrical equipment.
Warning
The devices described in this manual must be used only in applications prescribed
in this manual or in the respective technical descriptions, and only with certified
components and devices from third party manufacturers.
Warning
All respective safety measures and accident protection guidelines must be consid-
ered carefully and without exception.

D301171 - IO-Link master 1108 1-1
1 PROFIBUS-DP
System overview ..................................................................................................................2
Master/Slave system ......................................................................................................................... 2
System configuration and device types ............................................................................................ 2
– Single-Master systems ................................................................................................................... 3
– Multi-Master systems ..................................................................................................................... 3
Topology............................................................................................................................................ 3
Maximum system extension .............................................................................................................. 3
– Use of Drop lines ............................................................................................................................ 4
Transmission rate/Cycle times .......................................................................................................... 4
Transmission cables .......................................................................................................................... 4
– Cable types .................................................................................................................................... 5
– Installation guidelines ..................................................................................................................... 5
– Checking the PROFIBUS cabling ................................................................................................... 5
Diagnostic functions .......................................................................................................................... 5
Sync and Freeze Mode...................................................................................................................... 6
– Sync Mode ..................................................................................................................................... 6
– Freeze Mode .................................................................................................................................. 6
System performance ......................................................................................................................... 6
– Data transfer between DPM1 and the DP slaves ........................................................................... 7
– Protective mechanisms .................................................................................................................. 7
– Ident. number ................................................................................................................................. 8
GSD files ............................................................................................................................................ 8
Short Description of PROFIBUS-DPV1 .................................................................................9
General .............................................................................................................................................. 9
Acyclic data transfer .......................................................................................................................... 9
DPV1-functions.................................................................................................................................. 9
DPM1 versus DPM2 .......................................................................................................................... 9
Addressing the data using acyclic services..................................................................................... 10

PROFIBUS-DP
D301171 - IO-Link master 11081-2
System overview
PROFIBUS is a manufacturer-independent and open fieldbus standard for a wide area of
applications in factory and process automation. Manufacturer independence and openness
are guaranteed by the international standards EN 50170 and EN 50254. PROFIBUS enables
communication of devices of various manufacturers without requiring particular interface
adaptations.
PROFIBUS-DP (Decentral Periphery) is designed for data transfer between the control and
the input/output level. TURCK BL20 stations support PROFIBUS-DP.
PROFIBUS-DP is the speed-optimized PROFIBUS version, specially designed for communi-
cation between automation devices and decentralized peripheral devices. PROFIBUS-DP is
suited to replace cost-intensive parallel signal transmission via digital and analogue sensors
and actuators.
PROFIBUS-DP is based on DIN 19245, part 1 and part 4. During the course of European
fieldbus standardization, PROFIBUS-DP has been integrated into the European fieldbus stan-
dard EN 50170.
Master/Slave system
PROFIBUS-DP is a master/slave system, which consists of a master (usually integrated in the
PLC) and up to 31 slaves per segment. During operation, the master constantly scans the
connected slave stations. Several masters may be connected within a single network; this
would then be classified as a multi-master system. In this case they pass on their transmission
permission (Token Passing).
PROFIBUS-DP uses a bit transmission layer (Physical Layer) based on the industrially proven
RS485 standard.
System configuration and device types
PROFIBUS-DP is suited for both mono-master or multi-master system configuration. Thus a
high level of flexibility in system configuration is guaranteed. The network comprises 126
devices max. (master or slaves).
Configurable system parameters include the number of stations, the assignment of the station
address to the I/O addresses, data consistence of I/O data, format of diagnostic messages
and the bus parameters used. Every PROFIBUS-DP system consists of different types of
devices.
One distinguishes between three device types:
DP master class 1 (DPM1)
This is a central control, which exchanges data in a defined message cycle with the remote
stations (slaves). Typical devices are, for instance, programmable logic controllers (PLCs) or
PCs.
DP master class 2 (DPM2)
Devices of this type are engineering, configuration or operating devices. They are used during
set-up, maintenance and diagnosis, to configure the connected devices, to evaluate para-
meters and to scan the device status.
DP slave
A PROFIBUS-DP slave is a peripheral device (I/Os, drives, transducers), which reads input
data and provides output data to the periphery. Of course, there are also devices which
provide only input or only output data. The input and output data volume depends on the
specific device and may comprise up to 244 bytes input data and 244 bytes output data.

D301171 - IO-Link master 1108 1-3
System overview
1
Single-Master systems
With mono-master systems merely a single master on the bus is active during bus operation.
The PLC is the central control component. The slaves are coupled decentrally to the PLC via
the transmission medium. With this type of system configuration the shortest bus cycle times
are achieved.
Multi-Master systems
In multi-master operation there are several masters on the bus. These form independent sub-
systems, consisting of one DPM1 each and the associated slaves, or additional configuration
and diagnostic devices. The slave input and output data can be read by all DP masters.
Writing of outputs is reserved to a single DP master (the assigned DPM1 during configuration).
Multi-Master systems achieve an average bus cycle time. In time-critical applications you
should monitor the bus cycle time via a connected diagnostic tool.
Topology
PROFIBUS-DP communicates via a shielded 2-wire cable according to the RS485 standard.
The network topology accords to a line structure with active bus terminators on both ends.
Maximum system extension
PROFIBUS-DP is suited for connection of a large number of I/O points. Up to 126 addressable
bus nodes enable connection of thousands of analogue and digital I/O points within a
network.
PROFIBUS-DP allows a maximum of 32 nodes per segment; please note that masters and
repeaters always count as nodes. One segment is defined as the bus section between two
repeaters. If no repeaters are used, the entire network corresponds to one segment.
Segments must comply with the specified maximum length and the specified transmission
rates. Up to nine repeaters, type "REP-DP0002" may be connected within a network. The
maximum length of a bus line within a segment and the number of repeaters are listed in the
following table.
Table 1:
Maximum
System expan-
sion
PROFIBUS-DP
Communication rate Length of bus line Max. no. of
repeaters
Max. no. of nodes
9.6 kbps 1200 m 2 126
19,2 kbps 1200 m 2 126
93,75 kbps 1200 m 2 126
187,5 kbps 1000 m 2 126
500 kbps 400 m 4 126
1.5 Mbps 200 m 6 126
12 Mbps 100 m 9 126
Attention
The maximum number of 32 bus nodes may not be exceeded without a repeater.

PROFIBUS-DP
D301171 - IO-Link master 11081-4
Use of Drop lines
Transmission rate/Cycle times
The transmission rate set by the PROFIBUS-DP master determines the system's transmission
speed. Depending on the gateway, the transmission speed can be adjusted in a range of 9,6
kbps up to 12 Mbps.
Transmission cables
The bus nodes are interconnected via fieldbus cables, which accord to RS485 specifications
and DIN19 245. The cables must thus have the following characteristics:
Note
The length of drop lines may not exceed 6.6 m at a transmission speed of 1.5 Mbps.
At a transmission speed of 12 Mbps it is not permitted to use drop lines.
Table 2:
Characteristics
of PROFIBUS-
DP transmission
cables
Parameters Cable type A (DIN 19 245 part 3)
Wave resistance 135 to 165 Ω(3 to 20 MHz)
Capacitance < 30 pF/km
Loop resistance < 110 Ω/km
Conductor diameter > 0.64 mm
Conductor cross section > 0.34 mm2
Terminating resistors 220 Ω
Attention
The higher the transmission rate, the higher the number of bus nodes and the longer
the transmission cables, the more important to observe these parameters.
Figure 1:
Schematic
PROFIBUS-DP
cables
Schirm
Rt
Abschluß-
widerstand
Teilnehmer 0 Teilnehmer 31
innenliegend:
verdrillte Zweidrahtleitung
Rt
Vp Vp
GND GND
Shield inside:
Twisted cable pair
Rt
terminating
resistor
Station 0 Station 31
Rt
Vp Vp
GND GND

D301171 - IO-Link master 1108 1-5
System overview
1
Cable types
The bus cable of the PROFIBUS-DP network is a special shielded twisted data cable
according to RS485 standards. The data transmission rate is 12 Mbps max.
Installation guidelines
When mounting the modules and routing the cables please observe the technical guidelines
of the PROFIBUS user organization concerning PROFIBUS-DP/FMS (see
www.profibus.com).
Checking the PROFIBUS cabling
A PROFIBUS cable (or the cable segment if repeaters are used) can be tested with a few resis-
tance measurements. For this the cable should be disconnected from all stations:
Resistance between "A" and "B" at the beginning of the cable: approx. 110 Ω
Resistance between "A" and "B" at the end of the cable: approx. 110 Ω
Resistance between "A" at the beginning and "A" at the end of the cable: approx. 0 Ω
Resistance between "B" at the beginning and "B" at the end of the cable: approx. 0 Ω
Resistance between shield at the beginning and shield at the end of the cable: approx. 0 Ω
If these measurements are successful, then the cable can be used according to standards.
However, if there are further disturbances on the bus, electromagnetic interference should be
considered as cause. Please also observe the installation guidelines of the PROFIBUS user
organization (www.profibus.com)
Diagnostic functions
The comprehensive diagnostic functions of PROFIBUS-DP allow fast error localization.
The PROFIBUS-DP diagnosis is divided into three levels:
The PROFIBUS slaves of the BL20 series support the diagnostic functions of PROFIBUS-DP.
Note
Premoulded PROFIBUS-DP cables simplify network installation, shorten set-up
times and reduce wiring errors. TURCK offers an extensive and varied product
spectrum for this purpose.
The ordering information on the available cable types can be taken from the respec-
tive product catalogue.
Table 3:
PROFIBUS-DP
diagnosis
Type of diagnosis Description
station-related diagnostics Messages concerning the general operational readiness of a
bus node.
Module-related
diagnostics
These messages indicate that there is a diagnostic message
within the a certain I/O area (e.g. 8 bit output module) of a bus
node.
Channel-related diagnos-
tics
Here the error cause of a single input/output bit, i.e. relating to
a single channel, is indicated.
Example: "Short-circuit at output 2"

PROFIBUS-DP
D301171 - IO-Link master 11081-6
The evaluation of the diagnostic data via the control depends on the support of the master.
Sync and Freeze Mode
In addition to the node-specific user data traffic, which is automatically controlled by the
DPM1, the DP master has the possibility to send control commands to a slave, a group of
slaves, or simultaneously to all DP slaves. These control commands are transmitted as multi-
cast messages.
The Sync and Freeze mode for synchronization of the DP slaves can be determined via the
control commands. They enable event-controlled synchronization of the DP slaves.
Sync Mode
The DP slaves initiate the Sync mode upon receipt of a Sync control command from the
assigned DP master. In this mode, all addressed DP slaves "freeze" their present output
status.
During the following user data transfer cycles, the output data are stored by the DP slaves,
while the output states are retained. Only after receipt of the next Sync control command from
the master, the stored output data are switched through to the outputs.
The Sync mode is terminated upon an Unsync control command.
Freeze Mode
The Freeze control command induces the addressed DP slaves to assume the Freeze mode.
In this mode, the momentary values of the input states are "frozen". Input data will only be
updated upon receipt of the next freeze command from the DP master by the affected
devices.
The Freeze mode is terminated upon an Unfreeze control command.
System performance
In order to achieve a relatively high level of device interchangeability, the PROFIBUS-DP
system performance has also been standardized. It is largely determined by the operating
status of the DPM1. This can be either controlled locally or via the bus from the configuration
device.
One distinguishes between three major conditions:
Note
Further information on diagnostics can be taken from the device descriptions of the
master interfaces of the various manufacturers.
Table 4:
Operating
modes
Operating mode Description
Stop There is no data transfer between the DPM1 and the DP slaves. The
coupling module merely addresses the modules once after power-up
(none of the I/O LEDs illuminate).
Clear The DPM1 reads the input data of the DP slaves and retains the
outputs of the DP slaves in the safe state (depending on the reaction
to fieldbus errors, the green I/O LED illuminates and the outputs are
set).
Operate The DPM1 is in the data transfer phase. During cyclic data exchange
the inputs of the DP slaves are read and the output information is
transferred to the DP slaves (the green I/O LED illuminates).

D301171 - IO-Link master 1108 1-7
System overview
1
The DPM1 sends its local status within a configurable time interval via a multi-master
command to all assigned DP slaves. The system response to an error in the data transfer
phase of the DPM1, e.g. a failure of a DP slave, is determined by the operating parameter
"Auto-Clear". If this parameter is set to "True", then the DPM1 switches all outputs of the
assigned DP slaves to the safe status, as soon as a DP slave is no longer capable of user data
transfer. Then the DPM1 changes to the "Clear" state. If this parameter is set to "False", then
the DPM1 will retain its operating condition also in the event of an error and the user can
determine the system response.
Data transfer between DPM1 and the DP slaves
Data exchange between the DPM1 and the assigned DP slaves is automatically controlled by
the DPM1 in a determined fixed order. During configuration of the bus system, the user
assigns the DP slaves to the DPM1. It is also defined which DP slaves are to be included in
or excluded from cyclic user data transfer.
Data exchange between DPM1 and the DP slaves can be divided into the phases parameter-
ization, configuration and data transfer.
Prior to including a DP slave in the data transfer phase, the DPM1 checks during the param-
eterization and configuration phase, whether the programmed required configuration
complies with the actual device configuration. This check is used to verify that the device
type, the format and length information as well as the number of inputs and outputs accord.
The user thus is securely protected against parameterization errors. Additionally to the user
data transfer, which is automatically effected by the DPM1, it is also possible to send new
parameters to the DP slaves upon request of the user.
Protective mechanisms
In the decentralized periphery it is required to provide the system with highly effective protec-
tive functions against faulty parameterization or failure of the transmission devices.
PROFIBUS-DP applies certain mechanisms to monitor the DP master and the DP slaves.
These can be described as time monitoring functions. The monitoring interval is determined
during system configuration.

PROFIBUS-DP
D301171 - IO-Link master 11081-8
Ident. number
Each DP slave and each DPM1 must have an individual ident. number. It is needed so that
the DP master can identify the connected devices directly without creating significant
protocol overhead. The master compares the ident. numbers of the connected DP devices
with the ident. numbers registered in the configuration data of the DPM2. User data transfer
will only be started, if the right device types with the right station addresses are connected to
the bus. This provides additional protection against configuration errors. The manufacturer
specific ident. nos. are determined and assigned by the PROFIBUS user organization (PNO).
The PNO governs the ident. nos. together with the GSD files.
GSD files
Each PROFIBUS-DP module has a so-called GSD file (German abbr. for device data base file)
that comprises detailed information on the module: I/O data volume, transmission rates, revi-
sion status etc. This GSD file is needed to configure the station within the PROFIBUS-DP
system.
The GSD files can be downloaded via the TURCK website under www.turck.com.
Table 5:
Protective
mechanisms
Protective mecha-
nisms
Description
Of the
DP master
The DPM1 controls the user data transfer of the slaves via the
Data_Control_Timer. Each assigned slaves has a monitoring timer of
its own. The timer actuates if no user data are transferred correctly
during a certain time interval. In this case the user is informed on this
condition. If automatic error response (Auto_Clear = True) is enabled,
the DPM1 terminates the "Operate" status, switches the outputs of
the assigned slaves into the safe status and returns to the operating
status "Clear".
Of the
DP slave
The slave carries out response monitoring to detect master or trans-
mission errors. If there is no data exchange during the response moni-
toring interval with the associated master, the slave automatically
switches the outputs into the safe status. In multi-master system
operation, an additional access protection is required for the inputs
and outputs of the slaves, in order to ensure that only the authorized
master has direct access. The slaves provide an input and output
image for all other masters so that this map can be read by any
master, even without access token.

D301171 - IO-Link master 1108 1-9
Short Description of PROFIBUS-DPV1
1
Short Description of PROFIBUS-DPV1
General
PROFIBUS-DPV1 is an enhancement of PROFIBUS-DP which provides the possibility of
acyclic data communication.
A cyclic and centrally directed data transfer between master and slaves is characteristic for
the standard functions of PROFIBUS-DP. A Class1 master (PLC) controls the cyclic exchange
of process data with the slaves. The data exchange is carried out in rotation and in a defined
order. The data which have to be transmitted are projected beforehand.
Via acyclic communication functions, PROFIBUS-DPV1 now offers the possibility to transmit
data to the slave in addition to the cyclic process data.
Acyclic data transfer
The need for acyclic data transfer exists wherever slave devices which provide several param-
eterization options have to be parameterized during operation.
Typical examples are the parameters of a drive, like limit values, rotational speed or torque,
operation mode and the generation of an error list.
Acyclic services are handled with low priority, parallelly and additionally to the cyclic process
data transfer. The negative influence on the speed of the high-priority process data transfer,
shall thus be minimized.
DPV1-functions
The DPV1-functions consist basically of the services "Read" and "Write". The master uses
these services for read- or write access to data blocks in PROFIBUS.
In addition to that, an "intiate" and "abort"-service for the connection management, a "data-
transport"-service for the exchange of large data packages and the "alarm"-and "status"-
services for the transmission of alarm messages have been defined.
DPM1 versus DPM2
PROFIBUS-DPV1 differentiates between two master classes.
An automation system (PLC), which generally controls the basic cyclic process data transfer
with standard DP-functions, is defined as Class1-master. A Class1-master can use DPV1-
functions optionally.
The new Class2-master is generally an engineering tool which is used for the acyclic data
transfer.
The protocol cycle of the DPV1-functions on the fieldbus depends on the use of a Class1- or
a Class2-master.
Note
At present, the BLxx-gateways for DPV1 only support the services "Read" and
"Write".