rotork Modbus User manual

Publication PUB091-004-00_0918
Modbus RTU Actuator Control
Mk 3 Option Card
Technical Manual
(IQ3, SI3, CVA, CMA, K-Range)

Modbus MFU Option Card Installation Manual
2 of 64 Publication PUB091-004-00_0918
The Modbus card described in this manual has been designed to fully comply with Modbus
protocol specifications. This means that network biasing must be used somewhere on the
highway to ensure good communications. See Section 4.
The Modbus card described in this manual contains static-sensitive devices. Suitable
precautions, such as wearing an earthed anti-static wrist strap, should be taken before
handling the card. It should be kept in an anti-static bag or box while it is not fitted within an
actuator.
Note 1: The Modbus Modules described in this manual are suitable for inclusion in Rotork
IQ3, SI₃, CVA (Only firmware version CVA1.14 or later), CMA and K-range actuators.
Note 2: Although the same Modbus module is fitted to the different ranges of actuators, there
will be different numbers of valid inputs and outputs for each range, depending on the actuator
capabilities. For example, actuators not fitted with a battery cannot report Battery Low.
Note 3: The information in this manual relates to the following Modbus module firmware
version: V0050 or later.
Note 4: Throughout this manual the Modbus Module may simply be referred to as the module,
card or MFU (Modbus Field Unit –the circuit board fitted to the actuator in the field).
Note 5: Inputs are the status messages from the actuator and outputs are the command
messages to the actuator.
As we are continually developing our products their design is subject to change without notice.
©The contents of this document are copyright and must not be reproduced without the written
permission of Rotork Controls Ltd.
The names Allen, Bluetooth, Modbus, Rotork and Torx are registered trademarks.

Contents
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Contents
Glossary of Terms: ............................................................................................................................ 5
Abbreviations:.................................................................................................................................... 6
1INTRODUCTION............................................................................................ 7
1.1 General..................................................................................................................................... 8
2MODBUS OPTION CARD PROPERTIES...................................................... 9
2.1 Mechanical properties............................................................................................................ 9
2.2 Electrical Properties ............................................................................................................. 10
2.3Operation and Storage ......................................................................................................... 10
3Fitting the Modbus module Option Card .................................................. 11
3.1 Inside an IQ3 actuator .......................................................................................................... 11
3.2Replacing or Fitting a Modbus Module Option Card......................................................... 11
3.3 Inside an SI₃actuator............................................................................................................ 12
3.4 Inside a CVA actuator........................................................................................................... 13
3.5Inside a CMA actuator .......................................................................................................... 14
3.6 Inside a K-Range actuator.................................................................................................... 18
4RS-485 Data Highway, Connections and MFU Setup .............................. 19
4.1 Data Highway......................................................................................................................... 19
4.2 Highway Topology................................................................................................................ 20
4.3 Cable Types........................................................................................................................... 21
4.4 Termination Network ............................................................................................................ 22
4.5 Inter-connecting the Highway and Setting up the MFU .................................................... 23
4.5.1 Single Highway................................................................................................................ 23
4.5.2 Dual Highway................................................................................................................... 23
4.5.3 Single Highway with Internal Repeater............................................................................ 24
5The Actuator Input and Output Signals.................................................... 25
5.1 Control Outputs..................................................................................................................... 25
5.1.1 Controls Priority ............................................................................................................... 29
5.1.2 Modbus Control using Individual Coil commands............................................................ 29
5.1.3 Modbus Control using the ACTCON Register................................................................. 30
5.1.4 Modbus Control using the Actuator Position DV register ................................................ 30
5.1.5 The IQ3 ‘S’ contacts (Modbus DOs). ............................................................................... 30
5.1.6 IQ3 Modbus Network Control Disable feature................................................................. 31
5.2 Actuator Digital Input Status Feedback.............................................................................. 31
5.2.1 Digital Inputs from the Actuator ....................................................................................... 32
5.3 Actuator Analogue Input Feedback .................................................................................... 36
5.4 IQ3 Data Logger Information ............................................................................................... 36
6Modbus Communication............................................................................ 39
6.1 Electrical Specification......................................................................................................... 39

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6.2 Outer Protocol....................................................................................................................... 39
6.3 Repeaters............................................................................................................................... 39
6.4 Dual Channel Mode............................................................................................................... 40
7Modbus Database....................................................................................... 41
7.1 Modbus RTU Message Frame.............................................................................................. 41
7.2 Modbus Address................................................................................................................... 41
7.3 Function Code Support ........................................................................................................ 42
7.4 Broadcast Commands.......................................................................................................... 44
7.5 Data Location Offsets........................................................................................................... 44
7.6Data Locations ...................................................................................................................... 44
7.6.1 Data Accessed with Function Code 01 - Read Coils....................................................... 44
7.6.2 Data Accessed with Function Code 02 - Read Discrete Inputs....................................... 45
7.6.3 Data Accessed with Function Code 03 - Read Holding Registers .................................. 46
7.6.4 Data Accessed with Function Code 04 - Read Input Registers ...................................... 48
7.6.5 Data Accessed with Function Code 05 and 15 –Force Single and Multiple Coils.......... 49
7.6.6 Data Accessed with Function Code 06 and 16 –Preset Single and Multiple Registers . 49
7.6.7 Data Accessed with Function Code 07 –Read Exception Status................................... 49
7.6.8 Data Accessed with Function Code 08 –Loopback Diagnostic Test.............................. 50
7.6.9 Data Accessed with Function Code 17 –Report Slave ID.............................................. 50
7.7 Database Summary:.............................................................................................................. 51
7.8 Configuration Registers ....................................................................................................... 53
7.9 Actuator Related Configurable Parameter Registers........................................................ 54
7.9.1 Action on Loss of Comms (Register 7)............................................................................ 55
7.9.2 Limited Range Position Minimum and Maximum (Registers 8 and 9)............................. 55
7.9.3 Deadband and Hysteresis (Registers 10 and 14)............................................................ 55
7.9.4 Motion Inhibit Timer (MIT) (Register 11).......................................................................... 57
7.9.5 Auxiliary Input Mask (Register 12)................................................................................... 57
7.9.6 Comms Lost Position (Register 13)................................................................................. 58
7.9.7 ESD DI-4/Net Disable (Register 19)................................................................................ 58
7.9.8 Analogue Input Max/Min (Register 20)............................................................................ 58
7.9.9 Comms Fault Timer (Register 21) ................................................................................... 58
7.10 Modbus Network Related Configurable Parameter Registers...................................... 59
7.10.1 Modbus Address (Register 22)........................................................................................ 59
7.10.2 Baud Rate (Register 23).................................................................................................. 59
7.10.3 Parity and Stop Bits (Register 24) ................................................................................... 59
7.10.4 Termination (Register 25)................................................................................................ 59
7.10.5 Actuator Tag Name (Register 26 to 31)........................................................................... 59
8Setting Up and Maintaining the MFU ........................................................ 61
8.1 Using a Network Configuration Tool................................................................................... 61
8.2 Setting up an IQ3 with the Setting Tool.............................................................................. 61
8.3 Maintenance and Repair....................................................................................................... 62
8.4 Records.................................................................................................................................. 62
8.5 Troubleshooting.................................................................................................................... 63

Contents
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Table of Figures
Fig 1: The Modbus Module Option Card Actuator Compatibility..................................................... 7
Fig 2: The Modbus Field Unit .......................................................................................................... 9
Fig 3: The MFU and its location behind the control module in an IQ3.......................................... 11
Fig 4: The MFU located on the underside of the control PCB in a CVA actuator......................... 13
Fig 5: The MFU located in a CMA actuator................................................................................... 14
Fig 6: CMA menu structure for setting up the actuator: start at the BASIC setting....................... 15
Fig 7: CMA menu structure for setting up the actuator: from the ADVANC setting, ..................... 16
Fig 8: CMA menu structure for setting up the actuator: from the COMMS setting,....................... 17
Fig 9: Connections to the MFU located in a CMA actuator........................................................... 17
Fig 10: The MFU located in a K-Range actuator............................................................................. 18
Fig 11: Typical RS-485 Data Highway ............................................................................................ 19
Fig 12: RS-485 Data Highway Topology......................................................................................... 20
Fig 13: Typical RS-485 cable .......................................................................................................... 21
Fig 14: Active Termination for RS-485 highway. Biasing resistor values are typical...................... 22
Fig 15: Input and Output Data Direction.......................................................................................... 25
Fig 16: IQ3 Control Priorities........................................................................................................... 29
Fig 17: Modbus transaction format.................................................................................................. 41
Fig 18: Limited Range Position Control and Reporting................................................................... 55
Fig 19: Deadband and Hysteresis settings...................................................................................... 56
Glossary of Terms:
Address The unique address for a node on a particular highway of the fieldbus.
The address range is 1-247.
Enlight A graphical user interface for Bluetooth communication with CVA
actuators. This is downloadable from the Rotork web site,
www.rotork.com
Fieldbus The digital, two-way, multi-drop communication links.
Field Unit The Modbus Mk 3 option card fitted to the actuator.
Insight2 A graphical user interface for communication with IQ3, SI3and CVA
actuators. This is downloadable from the Rotork web site,
www.rotork.com
Interoperability The capability for a device from one manufacturer to interact with that
of another manufacturer, on a fieldbus network, without loss of
functionality.
Master/Slave Method of communication used by the Modbus Module. The fieldbus
requires a Modbus master to control the data exchange on the
highway.
Modbus The communication protocol used for data exchange, as defined in
IEC 61850.
Modbus RTU The version of the protocol used by the Rotork module.
Node A single device on the fieldbus.
Parity Bit added to data for error detection.

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Partial Stroke Test Moving a little-used valve by a small percentage from an end limit and
then returning it, proving that it will operate when required. Safety
related.
RS-485 The electrical properties of the data highway as defined by the IEC
8482 standard, copper conductors, 2-wire twisted pair.
Segment A section of an RS-485 fieldbus that is terminated at each end in its
characteristic impedance. Each Segment can include up to 32 devices
with unitary load.
Abbreviations:
ACTCON Actuator Control (Register).
CMA Compact Modulating Actuator.
Comms Communications.
CRC Cyclic Redundancy Check (error detection).
CVA Control Valve Actuator.
CVL Linear version of CVA.
CVQ Quarter-turn version of CVA.
DIO 1 Digital Input / Output Board, type 1.
DIO 2 Digital Input / Output Board, type 2.
DV Desired Value.
ESD Emergency Shut Down.
IEC International Electrotechnical Commission.
MFU Modbus Field Unit.
MV Measured Value.
PCB Printed Circuit Board.
PLC Programmable Logic Controller.
RAM Random Access Memory.
RIRO 1 Remote Input / Remote Output Board, Type 1.
RIRO 2 Remote Input / Remote Output Board, Type 2.
ROM Read Only Memory.
RTU Remote Terminal Unit.
SW Software.
UPS Uninterruptible Power Supply (CVA only).

Introduction
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1 INTRODUCTION
The Rotork Modbus Module Actuator Field Control option card (MFU) uses 2-wire (half duplex) RS-
485 and the Modbus RTU protocol to allow for information exchange and control over the data
highway between the actuator and a suitable host system with a Modbus capability.
The module is an integral part of the actuator in which it is housed and is fitted within the main
electrical housing. For the IQ3, CVA and K-Range products, this electrical housing is double-sealed
and need not be opened once the actuator leaves the assembly plant. The CMA range of actuators
does not have double sealing and the electrical cover is required to be opened for connecting to Field
connections.
All adjustments to the settings for the module may be made via the Modbus data highway using a
Modbus master tool or via the Infra-red or Bluetooth actuator setting tools for those products that
support those interfaces.
The settings which must be correct for communication are: address, baud rate, parity and stop bits.
These are described in Section 6. The default values are: address 247, baud rate 9600, parity None
and stop bits 1.
The Modbus Module circuits do not impinge on the actuator control electronics; the actuator itself
remaining fully self-protecting. The module performs the tasks of network interface, actuator data
collection and the issuing of actuator commands.
The Modbus Module may command the actuator into which it is fitted to: open, stop, close, perform an
ESD operation, perform a partial stroke test (IQ3 only) or move to a set position. Commands to the
module come from the network and will have been generated in a master controller. The module
operates as a slave in Master/Slave communication mode only, using the Modbus RTU protocol.
Fig 1: The Modbus Module Option Card Actuator Compatibility
IQ3
CVA
K-Range
CMA
SI3

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1.1 General
The Modbus Module has three variants:
Single RS-485 highway
Dual Independent isolated RS-485 highways
Single RS-485 highway with inbuilt isolating repeater
Communication Medium RS-485 2-wire highway (single or dual), half duplex
Protocol Modbus RTU
Mode Master/Slave; module is a slave.

Modbus Option Card Properties
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2 MODBUS OPTION CARD PROPERTIES
2.1 Mechanical properties
The Modbus module option card differs from all previous versions in that it interfaces directly between
the Modbus RTU network and the communication protocol used within the actuator. There is no
intermediate circuit board that it plugs into. We refer to it as the Modbus Field Unit, MFU.
The MFU is a single rectangular printed circuit board that fits inside the actuator electrical housing. It
connects directly to the Control Module PCB of the actuator by a ten pin connector (10 way header,
SK2). The field unit should be carefully fitted so that the connectors mate correctly. The actuator
internal wiring harness connects the field unit at SK3 to the Modbus highway via the actuator terminal
bung. The connector is polarised to prevent incorrect connection.
In the IQ3, the field unit can be fitted directly to the Control Module PCB using either one of the 2 slots
available, or can be fitted on top of another option module that may already be fitted in one of these
slots. There are 4 available slots for option cards to be mounted either directly or indirectly behind the
Control Module PCB.
Fig 2: The Modbus Field Unit
SK3 –Field
connections.
Control board
connection. SK2
connector fitted on
underside of MFU.

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2.2 Electrical Properties
The MFU processor circuits communicate to other modules in the actuator via an internal
communications bus. The MFU does not sit in the main control path for the actuator and does not
affect the actuator control integrity. The MFU processor contains the firmware for the unit. The
firmware version is indicated on the label fitted to the processor. It can also be read from the actuator
using the setting tool, by using Insight with Infra-red or by using Insight2 with Bluetooth, where
appropriate.
Additionally, the circuit includes non-volatile memory that is used to store specific field unit
communications settings.
The Modbus RS-485 fieldbus data highway connections are fully isolated from the actuator
electronics.
2.3 Operation and Storage
The MFU is designed to be stored in the actuator and operated within the same environment as the
actuator. The constraints are:
Operating temperature: -40deg C to +70deg C
Storage temperature: -50deg C to +85deg C
Relative Humidity: 5% to 95% (<50deg C) non-condensing