Danfoss Modbus RTU Operating guide

Download

MAKING MODERN LIVING POSSIBLE

Operating Instructions

Modbus RTU

Contents Modbus RTU Operating Instruction

Contents

1 Safety and Conformity

1.1 Safety Precautions

1.1.1 Safety Precautions - Continued 3

1.2.1 Caution 4

1.3.1 Software Version 4

1.4 CE Labelling

1.4.1 CE Conformity and Labelling 5

1.4.2 What Is Covered 5

1.4.3 Danfoss Frequency Converter and CE Labelling 5

1.4.4 Compliance with EMC Directive 2004/108/ECEMC Directive 2004/108/EC 6

1.5.1 Air Humidity 6

1.5.2 Aggressive Environments 6

1.5.3 Vibration and Shock 6

2 Introduction

2.1 Introduction

2.1.1 Modbus RTU Overview 8

3 3

8 8

3 RS-485 Installation and Set-up

3.1.1 Overview 9

3.1.2 Cable Specifications 9

3.1.5 EMC Precautions 11

4 Modbus RTU Message Framing Structure

4.1.1 Frequency Converter with Modbus RTU 12

4.1.2 Timing Constraints 12

4.1.3 Modbus RTU Message Structure 13

4.1.4 Start/Stop Field 13

4.1.5 Address Field 13

4.1.6 Function Field 13

4.1.7 Data Field 13

4.1.8 CRC Check Field 13

4.1.9 Coil and Register Addressing 14

4.1.10 Function Codes Supported by Modbus RTU 14

4.1.11 Coil Addresses 14

4.1.12 Register Addresses 16

4.1.13 Parameter Handling 16

4.1.14 Storage of Data 16

4.1.15 IND 16

4.1.16 Text Blocks 16

MG92B102 - VLT® is a registered Danfoss trademark 1

Contents Modbus RTU Operating Instruction

4.1.17 Conversion Factor 17

4.1.18 Parameter Values 17

5 How to Control the Frequency Converter

5.1 How to Control the Frequency Converter

5.2 Parameter for Modbus RTU

5.2.1 Important Parameters for Modbus RTU 18

5.2.2 Access via PCD write/read 18

5.2.3 Mapping the Holding Registers to Drive Parameters 19

5.2.4 Mapping the Holding Registers to Drive Parameters, 32 bits 20

6 Function Code Examples

6.1 Examples

6.1.2 Force/Write Single Coil (05 HEX) 21

6.1.3 Force/Write Multiple Coils (0F HEX) 21

6.1.4 Read Holding Registers (03 HEX) 22

6.1.5 Preset Single Register (06 HEX) 22

6.1.6 Preset Multiple Registers (10 HEX) 23

7 FC Control Profile

7.1.1 Control Word According to FC Profile (8-10 Protocol = FC profile) 24

18 18 18

21 21

8 Parameters

8.1 Parameters: 8-** Communications and Options

8.1.3 8-3* FC Port Settings 30

8.1.4 8-4* FC MC protocol set 31

9 Troubleshooting

9.1.1 Modbus Exception Codes 35

9.1.2 8-80 Bus Message count 35

9.1.3 8-81 Bus Error Count 35

9.1.4 8-82 Slave Messages Rcvd 35

9.1.5 8-83 Slave Error 36

Index

28 28

2 MG92B102 - VLT® is a registered Danfoss trademark

Safety and Conformity Modbus RTU Operating Instruction

1 Safety and Conformity

1.1 Safety Precautions

WARNING

The voltage of the frequency converter is dangerous whenever connected to mains. Incorrect installation of the motor, frequency converter or fieldbus may cause death, serious personal injury or damage to the equipment. Consequently, the instructions in this manual, as well as national and local rules and safety regulations, must be complied with.

Safety Regulations

1. The mains supply to the frequency converter must be disconnected whenever repair work is to be carried out. Check that the mains supply has been disconnected and that the necessary time has elapsed before removing motor and mains supply plugs.

2. The [Off] button on the control panel of the frequency converter does not disconnect the mains supply and consequently it must not be used as a safety switch.

3. The equipment must be properly earthed, the user must be protected against supply voltage and the motor must be protected against overload in accordance with applicable national and local regulations.

4. The earth leakage current exceeds 3.5 mA.

5. Protection against motor overload is not included in the factory setting. If this function is desired, set 1-90 Motor Thermal Protection to data value ETR trip 1 [4] or data value ETR warning 1 [3].

6. Do not remove the plugs for the motor and mains supply while the frequency converter is connected to mains. Check that the mains supply has been disconnected and that the necessary time has elapsed before removing motor and mains plugs.

7. Note that the frequency converter has more voltage sources than L1, L2 and L3, when load sharing (linking of DC intermediate circuit) or external 24 V DC are installed. Check that all voltage sources have been disconnected and that the necessary time has elapsed before commencing repair work.

1.1.1

Safety Precautions - Continued

Warning against unintended start

1. The motor can be brought to a stop with digital commands, bus commands, references or a local stop, while the frequency converter is connected to mains. If personal safety considerations (e.g. risk of personal injury caused by contact with moving machine parts following an unintentional start) make it necessary to ensure that no unintended start occurs, these stop functions are not sufficient. In such cases the mains supply must be disconnected or the Safe Stop function must be activated.

2. The motor may start while setting the parameters. If this means that personal safety may be compromised (e.g. personal injury caused by contact with moving machine parts), motor starting must be prevented, for instance by use of the Safe Stop function or secure disconnection of the motor connection.

3. A motor that has been stopped with the mains supply connected, may start if faults occur in the electronics of the frequency converter, through temporary overload or if a fault in the power supply grid or motor connection is remedied. If unintended start must be prevented for personal safety reasons (e.g. risk of injury caused by contact with moving machine parts), the normal stop functions of the frequency converter are not sufficient. In such cases the mains supply must be disconnected or the Safe Stop function must be activated.

NOTE

When using the Safe Stop function, always follow the instructions in the section Safe Stop of the Design Guide.

4. Control signals from, or internally within, the frequency converter may in rare cases be activated in error, be delayed or fail to occur entirely. When used in situations where safety is critical, e.g. when controlling the electromagnetic brake function of a hoist application, these control signals must not be relied on exclusively.

1 1

MG92B102 - VLT® is a registered Danfoss trademark 3

Safety and Conformity Modbus RTU Operating Instruction

WARNING

1.2.1 Caution

High Voltage

Touching the electrical parts may be fatal - even after the equipment has been disconnected from mains. Also make sure that other voltage inputs have been disconnected, such as external 24 V DC, load sharing (linkage of DC intermediate circuit), as well as the motor connection for kinetic back up. Systems where frequency converters are installed must, if necessary, be equipped with additional monitoring and protective devices according to the valid safety regulations, e.g law on mechanical tools, regulations for the prevention of accidents etc. Modifications on the frequency converters by means of the operating software are allowed.

CAUTION

The DC link capacitors remain charged after power has been disconnected. Be aware that there may be high voltage on the DC link even when the Control Card LEDs are turned off. A red LED is mounted on a circuit board inside the frequency converter to indicate the DC bus voltage. The red LED will stay lit until the DC link is 50 V DC or lower. To avoid electrical shock hazard, disconnect the frequency converter from mains before carrying out maintenance. When using a PM-motor, make sure it is disconnected. Before doing service on the frequency converter wait at least the amount of time indicated below:

NOTE

Hazardous situations shall be identified by the machine builder/integrator who is responsible for taking necessary preventive means into consideration. Additional monitoring and protective devices may be included, always according to valid national safety regulations, e.g. law on mechanical tools, regulations for the prevention of accidents.

NOTE

Crane, Lifts and Hoists: The controlling of external brakes must always have a redundant system. The frequency converter can in no circumstances be the primary safety circuit. Comply with relevant standards, e.g. Hoists and cranes: IEC 60204-32 Lifts: EN 81

Protection Mode Once a hardware limit on motor current or DC link voltage is exceeded the frequency converter will enter “Protection mode”. “Protection mode” means a change of the PWM modulation strategy and a low switching frequency to minimize losses. This continues 10 s after the last fault and increases the reliability and the robustness of the frequency converter while re-establishing full control of the motor. In hoist applications “Protection mode” is not usable because the frequency converter will usually not be able to leave this mode again and therefore it will extend the time before activating the brake – which is not recommendable. The “Protection mode” can be disabled by setting 14-26 Trip Delay at Inverter Fault to zero which means that the frequency converter will trip immediately if one of the hardware limits is exceeded.

Voltage [V] Power [kW] Waiting Time [min] 380-500 0.25-7.5 4 11-75 15 90-200 20 250-800 40 525-690 11-75 (frame

size B and C)

37-315 (frame

size D)

355-1000 30

1.2.2 Protection Mode

Equipment containing electrical components may not be disposed of together with domestic waste. It must be separately collected with electrical and electronic waste according to local and currently valid legislation.

1.3.1 Software Version

Design Guide

Software version: 6.4x

This Design Guide can be used for all frequency converters with software version 6.4x. The software version number can be seen from 15-43 Software Version.

NOTE

It is recommended to disable protection mode in hoisting applications (14-26 Trip Delay at Inverter Fault = 0)

4 MG92B102 - VLT® is a registered Danfoss trademark

Safety and Conformity Modbus RTU Operating Instruction

1.4 CE Labelling

1.4.1 CE Conformity and Labelling

The machinery directive (2006/42/EC) Frequency converters do not fall under the machinery directive. However, if a frequency converter is supplied for use in a machine, Danfoss provide information on safety aspects relating to the frequency converter. What is CE Conformity and Labelling? The purpose of CE labelling is to avoid technical trade obstacles within EFTA and the EU. The EU has introduced the CE label as a simple way of showing whether a product complies with the relevant EU directives. The CE label says nothing about the specifications or quality of the product. Frequency converters are regulated by two EU directives: The low-voltage directive (2006/95/EC) Frequency converters must be CE labelled in accordance with the low-voltage directive of January 1, 1997. The directive applies to all electrical equipment and appliances used in the 50 - 1000 V AC and the 75 - 1500 V DC voltage ranges. Danfoss CE-labels in accordance with the directive and issues a declaration of conformity upon request. The EMC directive (2004/108/EC) EMC is short for electromagnetic compatibility. The presence of electromagnetic compatibility means that the mutual interference between different components/ appliances does not affect the way the appliances work. The EMC directive came into effect January 1, 1996. Danfoss CE-labels in accordance with the directive and issues a declaration of conformity upon request. To carry out EMC-correct installation, see the instructions in this Design Guide. In addition, Danfoss specify which standards our products comply with. Danfoss offer the filters presented in the specifications and provide other types of assistance to ensure the optimum EMC result.

The frequency converter is most often used by professionals of the trade as a complex component forming part of a larger appliance, system or installation. The EMC directive (2004/108/EC)

What Is Covered

1.4.2

The EU "Guidelines on the Application of Council Directive 2004/108/EC" outline three typical situations of using a frequency converter. See below for EMC coverage and CE labelling.

1. The frequency converter is sold directly to the end-consumer. The frequency converter is for example sold to a DIY market. The end-consumer is a layman. Installing the frequency converter for

use with a hobby machine, a kitchen appliance, etc. For such applications, the frequency converter must be CE labelled in accordance with the EMC directive.

2. The frequency converter is sold for installation in a plant. The plant is built up by professionals of the trade. It could be a production plant or a heating/ventilation plant designed and installed by professionals of the trade. Neither the frequency converter nor the finished plant has to be CE labelled under the EMC directive. However, the unit must comply with the basic EMC requirements of the directive. This is ensured by using components, appliances, and systems that are CE labelled under the EMC directive.

3. The frequency converter is sold as part of a complete system. The system is being marketed as complete and could e.g. be an air-conditioning system. The complete system must be CE labelled in accordance with the EMC directive. The manufacturer can ensure CE labelling under the EMC directive either by using CE labelled components or by testing the EMC of the system. If only CE labelled components are used, it is unneccessary to test the entire system.

Danfoss Frequency Converter and CE

1.4.3 Labelling

CE labelling is a positive feature when used for its original purpose, i.e. to facilitate trade within the EU and EFTA.

However, CE labelling may cover many different specifications. Check what a given CE label specifically covers.

The covered specifications can be very different and a CE label may therefore give the installer a false feeling of security when using a frequency converter as a component in a system or an appliance.

Danfoss CE labels the frequency converters in accordance with the low-voltage directive. This means that if the frequency converter is installed correctly, we guarantee compliance with the low-voltage directive. Danfoss issues a declaration of conformity that confirms our CE labelling in accordance with the low-voltage directive.

The CE label also applies to the EMC directive provided that the instructions for EMC-correct installation and filtering are followed. On this basis, a declaration of conformity in accordance with the EMC directive is issued.

The Design Guide offers detailed instructions for installation to ensure EMC-correct installation. Furthermore,

1 1

MG92B102 - VLT® is a registered Danfoss trademark 5

Safety and Conformity Modbus RTU Operating Instruction

Danfoss specifies which our different products comply with.

Danfoss provides other types of assistance that can help to obtain the best EMC result.

1.4.4 Compliance with EMC Directive 2004/108/ECEMC Directive

IP54/55. As an extra protection, coated printed circuit boards can be ordered as an option.

Airborne Particles such as dust may cause mechanical, electrical, or thermal failure in the frequency converter. A typical indicator of excessive levels of airborne particles is dust particles around the frequency converter fan. In very dusty environments, use equipment with enclosure rating IP54/55 or a cabinet for IP00/IP20/TYPE 1 equipment.

2004/108/EC

In environments with high temperatures and humidity,

As mentioned, the frequency converter is mostly used by professionals of the trade as a complex component forming part of a larger appliance, system, or installation. Note that the responsibility for the final EMC properties of the appliance, system or installation rests with the installer. As an aid to the installer, Danfoss has prepared EMC installation guidelines for the Power Drive system. The standards and test levels stated for Power Drive systems are complied with, provided that the EMC-correct instructions for installation are followed, see the section EMC Immunity in the Design Guide.

Air Humidity

1.5.1

The frequency converter has been designed to meet the IEC/EN 60068-2-3 standard, EN 50178 pkt. 9.4.2.2 at 50° C.

corrosive gases such as sulphur, nitrogen, and chlorine compounds cause chemical processes on the frequency converter components.

Such chemical reactions rapidly affect and damage the electronic components. In such environments, mount the equipment in a cabinet with fresh air ventilation, keeping aggressive gases away from the frequency converter. An extra protection in such areas is a coating of the printed circuit boards, which can be ordered as an option.

NOTE

Mounting frequency converters in aggressive environments increases the risk of stoppages and considerably reduces the life of the converter.

Aggressive Environments

1.5.2

A frequency converter contains a large number of mechanical and electronic components. All are to some extent vulnerable to environmental effects.

CAUTION

The frequency converter should not be installed in environments with airborne liquids, particles, or gases capable of affecting and damaging the electronic components. Failure to take the necessary protective measures increases the risk of stoppages, thus reducing the life of the frequency converter.

Degree of protection as per IEC 60529 The Safe Stop function may only be installed and operated in a control cabinet with degree of protection IP54 or higher (or equivalent environment). This is required to avoid cross faults and short circuits between terminals, connectors, tracks and safety-related circuitry caused by foreign objects.

Liquids can be carried through the air and condense in the frequency converter and may cause corrosion of components and metal parts. Steam, oil, and salt water may cause corrosion of components and metal parts. In such environments, use equipment with enclosure rating

Before installing the frequency converter, check the ambient air for liquids, particles, and gases. This is done by observing existing installations in this environment. Typical indicators of harmful airborne liquids are water or oil on metal parts, or corrosion of metal parts.

Excessive dust particle levels are often found on installation cabinets and existing electrical installations. One indicator of aggressive airborne gases is blackening of copper rails and cable ends on existing installations.

D and E enclosures have a stainless steel back-channel option to provide additional protection in aggressive environments. Proper ventilation is still required for the internal components of the frequency converter. Contact Danfoss for additional information.

1.5.3

Vibration and Shock

The frequency converter has been tested according to the procedure based on the shown standards:

The frequency converter complies with requirements that exist for units mounted on the walls and floors of production premises, as well as in panels bolted to walls or floors.

6 MG92B102 - VLT® is a registered Danfoss trademark

Safety and Conformity Modbus RTU Operating Instruction

IEC/EN 60068-2-6: Vibration (sinusoidal) - 1970

•

IEC/EN 60068-2-64: Vibration, broad-band random

•

1 1

MG92B102 - VLT® is a registered Danfoss trademark 7

Introduction Modbus RTU Operating Instruction

2 Introduction

confirming the action taken, any data to be returned, and

2.1 Introduction

This manual explains how to physically establish and configure communication between the Danfoss FC Series and a controller using the Modbus RTU protocol.

This instruction is intended to be used for both instruction and reference. It only briefly touches on the basics of the Modbus protocol whenever necessary to gain an understanding of the Modbus RTU. This instruction is also intended to serve as a guideline to specify and optimise the communication system. Even experienced Modbus programmers, should read these entire operating instructions before starting programming since important information can be found in all sections.

Modbus RTU Overview

2.1.1

Regardless of the type of physical communication networks, the Modbus RTU Overview describes the process a controller uses to request access to another device. This process includes how the Modbus RTU responds to requests from another device, and how errors are detected and reported. It also establishes a common format for the layout and contents of message fields. During communications over a Modbus RTU network, the protocol determines:

an error-checking field. If an error occurs in receipt of the message, or if the slave is unable to perform the requested action, the slave constructs an error message, and sends it in response, or a time-out occurs.

How each controller learns its device address Recognizes a message addressed to it Determines which actions to take Extracts any data or other information contained

in the message

If a reply is required, the controller constructs the reply message and sends it. Controllers communicate using a master-slave technique in which only one device (the master) can initiate transactions (called queries). The other devices (slaves) respond by supplying the requested data to the master, or by taking the action requested in the query. The master can address individual slaves, or can initiate a broadcast message to all slaves. Slaves return a message (called a response) to queries that are addressed to them individually. No responses are returned to broadcast queries from the master. The Modbus RTU protocol establishes the format for the master’s query by placing into it the device (or broadcast) address, a function code defining the requested action, any data to be sent, and an error-checking field. The slave’s response message is also constructed using Modbus protocol. It contains fields

8 MG92B102 - VLT® is a registered Danfoss trademark

Wire # 1

Wire # 2

Data In Data Out

175ZB021.10

Wire #1

Wire #2

175ZB028.10

130BA060.11

68 69 68 69 68 69

RS 485

RS 232 USB

RS-485 Installation and Set... Modbus RTU Operating Instruction

3 RS-485 Installation and Set-up

3.1.1 Overview

The Modbus RTU protocol is based on the built-in RS-485 (EIA-485) interface on the FC Drive series control card. RS-485 is a two-wire bus-interface that allows multi-drop network topology i.e. nodes can be connected as a bus (daisy chain), or via drop cables from a common trunk line. Danfoss uses the two-wire system where the communication between master and slave is half-duplex, i.e. it cannot transmit and receive at the same time.

Each signal uses one twisted-pair line — two wires twisted around themselves. This is known as balanced data transmission or differential voltage transmission (see Illustration 3.1). The signal on one wire is ideally the exact opposite of the signal on the second wire. In other words, if one wire is transmitting a high, the other wire transmits a low, and vice versa (see Illustration 3.2). Since RS-485 is a multipoint communication system, all devices are connected to the single twisted-pair cable.

3.1.2 Cable Specifications

When choosing a transmission line for RS-485, it is necessary to examine the required distance of the cable and the data rate of the system. Losses in a transmission line are a combination of AC losses (skin effect), DC conductor loss, leakage, and AC losses in the dielectric. In high-quality cable, the conductor losses and the dielectric losses are on the same order of magnitude.

The recommended maximum Modbus cable length between the frequency converter and the Controller must not exceed 30 m (100 feet). While the RS-485 specification does not specify cabling, the recommendation is 0.25 mm2/24 AWG shielded twisted-pair cable with a shunt capacitance of 16 pF/ft and 100 Ω impedance. Another choice is the same cable commonly used in the twistedpair Ethernet cabling. This cable is commonly referred to as Category 5 cable. The cable has a maximum capacitance of 17 pF/ft (14.5 pF/ft typical) and characteristic impedance of 100 Ω.

Network Connection

3.1.3

Illustration 3.1 Balanced Data Transmission

Illustration 3.2 Differential Concept

The Modbus RTU uses master/slave architecture, where each slave device has its unique address and responds only to packets addressed to this device. The packets are generated by the master (Controller), which periodically polls all connected slave devices. Data travels over the single line in both directions.

According to the EIA-485 specification a total number of 32 nodes can be connected to one Modbus RTU network segment, and a total of 247 nodes in a network are supported. Network segments are divided with repeaters.

NOTE

Each repeater counts for a node in each segment it is installed. Every node connected to the same network must have a unique nodes address, across all segments.

One or more frequency converters can be connected to a control (or master) using the RS-485 standardized interface. Terminal 68 is connected to the P signal (TX+, RX+), while terminal 69 is connected to the N signal (TX-,RX-).

If more than one frequency converter is connected to a master, use parallel connections.

MG92B102 - VLT® is a registered Danfoss trademark 9

130BB021.10

12 13 18 19 27 29 32

33 20 37

Remove jumper to enable Safe Stop

61 68 69 39 42 50 53 54 55

130BT310.10

N O

V LT

BUS TER. OFF-ON

A53 A54 U- I U- I

RS-485 Installation and Set... Modbus RTU Operating Instruction

Illustration 3.3 Control Card Terminals

RS-485 Bus Termination

3.1.4

The RS-485 bus terminate by a resistor network at both ends only. For this purpose, set switch S801 on the control card for "On".

10 MG92B102 - VLT® is a registered Danfoss trademark

Fieldbus cable

Min.200mm

90° crossing

130BA080.11

RS-485 Installation and Set... Modbus RTU Operating Instruction

3.1.5 EMC Precautions

The following EMC precautions are recommended to achieve interference-free operation of the RS-485 network.

Relevant national and local regulations, for example regarding protective earth connection, must be observed. The RS-485 communication cable must be kept away from motor and brake resistor cables to avoid coupling of high frequency noise from one cable to another. Normally a distance of 200 mm (8 inches) is sufficient, but keeping the greatest possible distance between the cables is generally recommended, especially where cables run in parallel over long distances. When crossing is unavoidable, the RS-485 cable must cross motor and brake resistor cables at an angle of 90o.

MG92B102 - VLT® is a registered Danfoss trademark 11

at least 3.5 char

3.5 char

4.5 char

Frame 1 Frame 2 Frame 3

175ZB026.10

Frame 1 OK

≤ 1.5 char

> 1.5 char

Frame 2 NOK

175ZB027.10

Modbus RTU Message Framing ... Modbus RTU Operating Instruction

4 Modbus RTU Message Framing Structure

4.1.1 Frequency Converter with Modbus RTU

The controllers are set up to communicate on the Modbus network using RTU (Remote Terminal Unit) mode, with

each byte in a message containing 8-bit hexadecimal

Bits Per Byte 1 start bit

8 data bits, least significant bit sent first 1 bit for even/odd parity; no bit for no parity 1 stop bit if parity is used; 2 bits if no parity

characters. The format for each byte is shown in Table 4.1.

Start bit

Table 4.1 The Format for each Byte

Data byte Stop/

parity

Stop

4.1.2 Timing Constraints

The Modbus Standard specifies two timing constraints. Table 4.1 illustrates the inter-character timing which determines that a message has been received.

NOTE

if the baud rate is greater than 19200, then the 3.5 character time is replaced by a timeout time of 1.75 ms.

NOTE

It is very important that the controller wait at least 3.5 character length otherwise the nodes can not separate the telegrams.

There is an additional timing constraint, the framing error time, as shown in Illustration 4.1. The Modbus specification states that if a framing error occurs, the message should

frequency converter notes the occurrence of framing errors and maintains a counter for them, but it does not discard the message.

be considered invalid and discarded. The variable speed

12 MG92B102 - VLT® is a registered Danfoss trademark

Modbus RTU Message Framing ... Modbus RTU Operating Instruction

4.1.3 Modbus RTU Message Structure

The transmitting device places a Modbus RTU message into a frame with a known beginning and ending point. This allows receiving devices to begin at the start of the message, read the address portion, determine which device is addressed (or all devices, if the message is broadcast), and to recognise when the message is completed. Partial messages are detected and errors set as a result. Characters for transmission must be in hexadecimal 00 to FF format in each field. The frequency converter continuously monitors the network bus, also during ‘silent’ intervals. When the first field (the address field) is received, each frequency converter or device decodes it to determine which device is being addressed. Modbus RTU messages addressed to zero are broadcast messages. No response is permitted for broadcast messages. A typical message frame is shown in Table 4.2.

Start Address Function Data CRC

T1-T2-T3-T48 bits 8 bits N x 8

bits

check

16 bits T1-T2-T3-

End

address in this address field to let the master know which slave is responding.

4.1.6 Function Field

The function field of a message frame contains 8 bits. Valid codes are in the range of 1-FF. Function fields are used to send messages between master and slave. When a message is sent from a master to a slave device, the function code field tells the slave what kind of action to perform. When the slave responds to the master, it uses the function code field to indicate either a normal (errorfree) response, or that some kind of error occurred (called an exception response). For a normal response, the slave simply echoes the original function code. For an exception response, the slave returns a code that is equivalent to the original function code with its most significant bit set to logic 1. In addition, the slave places a unique code into the data field of the response message. This tells the master what kind of error occurred, or the reason for the exception. Also refer to the sections 4.1.10 Function Codes

Supported by Modbus RTU and 9.1.1 Modbus Exception Codes.

4 4

Table 4.2 Typical Modbus RTU Message Structure

Start/Stop Field

4.1.4

Messages start with a silent period of at least 3.5 character intervals. This is implemented as a multiple of character intervals at the selected network baud rate (shown as Start T1-T2-T3-T4). The first field to be transmitted is the device address. Following the last transmitted character, a similar period of at least 3.5 character intervals marks the end of the message. A new message can begin after this period. The entire message frame must be transmitted as a continuous stream. If a silent period of more than 1.5 character intervals occurs before completion of the frame, the receiving device flushes the incomplete message and assumes that the next byte will be the address field of a new message. Similarly, if a new message begins before

3.5 character intervals after a previous message, the

receiving device considers it a continuation of the previous message. This causes a time-out (no response from the slave), since the value in the final CRC field is not valid for the combined messages.

4.1.5

Address Field

The address field of a message frame contains 8 bits. Valid slave device addresses are in the range of 0 – 247 decimal. The individual slave devices are assigned addresses in the range of 1 – 247. (0 is reserved for broadcast mode, which all slaves recognize.) A master addresses a slave by placing the slave address in the address field of the message. When the slave sends its response, it places its own

Data Field

4.1.7

The data field is constructed using sets of two hexadecimal digits, in the range of 00 to FF hexadecimal. These are made up of one RTU character. The data field of messages sent from a master to slave device contains additional information which the slave must use to take the action defined by the function code. This can include items such as coil or register addresses, the quantity of items to be handled, and the count of actual data bytes in the field.

CRC Check Field

4.1.8

Messages include an error-checking field, operating on the basis of a Cyclical Redundancy Check (CRC) method. The CRC field checks the contents of the entire message. It is applied regardless of any parity check method used for the individual characters of the message. The CRC value is calculated by the transmitting device, which appends the CRC as the last field in the message. The receiving device recalculates a CRC during receipt of the message and compares the calculated value to the actual value received in the CRC field. If the two values are unequal, a bus timeout occurs. The error-checking field contains a 16-bit binary value implemented as two 8-bit bytes. When this is done, the low-order byte of the field is appended first, followed by the high-order byte. The CRC high-order byte is the last byte sent in the message.

MG92B102 - VLT® is a registered Danfoss trademark 13

Modbus RTU Message Framing ... Modbus RTU Operating Instruction

4.1.9 Coil and Register Addressing

In Modbus, all data are organized in coils and holding registers. Coils hold a single bit, whereas holding registers hold a 2-byte word (i.e. 16 bits). All data addresses in Modbus messages are referenced to zero. The first occurrence of a data item is addressed as item number zero. For example: The coil known as ‘coil 1’ in a programmable controller is addressed as coil 0000 in the

data address field of a Modbus message. Coil 127 decimal is addressed as coil 007EHEX (126 decimal). Holding register 40001 is addressed as register 0000 in the data address field of the message. The function code field already specifies a ‘holding register’ operation. Therefore, the ‘4XXXX’ reference is implicit. Holding register 40108 is addressed as register 006BHEX (107 decimal).

See 4.1.11 Coil Addresses for details regarding Coil Addresses and 4.1.12 Register Addresses for details

Function Read coils 1 hex Read holding registers 3 hex Write single coil 5 hex Write single register 6 hex Write multiple coils F hex Write multiple registers 10 hex Get comm. event counter B hex Report slave ID 11 hex

Function Function

Code

Diagnostics 8 1 Restart communication

Subfunction code

2 Return diagnostic register 10 Clear counters and

11 Return bus message

regarding Register Addresses

12 Return bus communi-

4.1.10

Danfoss FC Series Modbus RTU supports use of the

Function Codes Supported by Modbus RTU

13 Return bus exception

14 Return slave message

following function codes in the function field of a

Function Code

Sub-function

diagnostic register

count

cation error count

error count

count

message.

4.1.11 Coil Addresses

Table 4.3 shows the coils addresses. Notice that the coil known as ‘coil 1’ in a programmable controller is addressed as coil 0000 in the data address field of a Modbus message.

Coil Number Description Signal Direction 1-16 17-32 Frequency converter speed or set-point reference Range 0x0 – 0xFFFF (-200% ...

33-48 49-64 Open loop mode: Frequency converter output frequency Closed loop mode:

65 Parameter write control (master to slave) Master to slave

66-65536 Reserved

Table 4.3 Coil Addresses

Frequency converter control word (see Table 4.4)

~200%) Frequency converter status word (see Table 4.5)

frequency converter feedback signal

0 = Parameter changes are written to the RAM of the frequency

converter

1 = Parameter changes are written to the RAM and EEPROM of the

frequency converter.

Master to slave Master to slave

Slave to master Slave to master

14 MG92B102 - VLT® is a registered Danfoss trademark

Modbus RTU Message Framing ... Modbus RTU Operating Instruction

Control Word (FC profile) Coil 0 1 00 Reference value External selection lsb 01 Reference value External selection msb 02 DC brake Ramp 03 Coasting No coasting 04 Quick stop Ramp 05 Hold output frequency Use ramp 06 Ramp stop Start 07 No function Reset 08 No function Jog 09 Ramp 1 Ramp 2 10 Data invalid Data invalid 11 Relay 01 open Relay 01 active 12 Relay 02 open Relay 02 active 13 Parameter set-up Selection lsb 15 No function Reverse

Table 4.4 Control Word (FC profile)

Status Word (FC profile) Coil 0 1 00 Control not ready Control ready 01 Drive not ready Drive ready 02 Coasting Enable 03 No error Trip 04 No error Error (no trip) 05 Reserved 06 No error Triplock 07 No warning Warning 08 Speed # reference Speed = reference 09 Local operation Bus control 10 Out of frequency limit Frequency limit OK 11 No operation In operation 12 Drive OK Stopped, auto start 13 Voltage OK Voltage exceeded 14 Torque OK Torque exceeded 15 TImer OK Timer exceeded

4 4

Table 4.5 Status Word (FC profile)

See 7 FC Control Profile for detail on the Control word, reference, status word and Main Actual Value. The Coil 65 decimal determines whether data written to the frequency converter are stored in EEPROM and RAM (coil 65 = 1) or only in RAM (coil 65 =0). Notice that coil 65 needs to be set On before writing to register are stored in EEPROM.

MG92B102 - VLT® is a registered Danfoss trademark 15

Modbus RTU Message Framing ... Modbus RTU Operating Instruction

4.1.12 Register Addresses

Table 4.6 shows the register addresses.

Holding registers Modbus Register Number Description 00001-00006 Reserved 00007 Last error code from an FC data object interface

00008 Reserved 00009 Parameter index* 00010-00099 000 parameter group (parameters 001 through 099) 00100-00199 100 parameter group (parameters 100 through 199) 00200-00299 200 parameter group (parameters 200 through 299)

... ...

02810-02873 02910-02973

... ...

00300-00399 300 parameter group (parameters 300 through 399) 00400-00499 400 parameter group (parameters 400 through 499)

... ...

28000-28999 2800 parameter group (parameters 2800 through 2899)

... ...

50000 Control word (CTW) 50010 Bus reference (Ref) 50200 Status word (STW). 50210 Main Actual Value (MAV)

Write data block (PCD Write via 8-42 PCD write configuration) Read data block (PCD Read via 8-43 PCD read configuration)

4.1.13 Parameter Handling

Each parameter number is translated to a register address. The parameter number is translated to Modbus holding address as parameter number x 10 DECIMAL. Notice that holding register 40001 is addressed as register 0000 in the data address field of the message. The function code field already specifies a ‘holding register’ operation. Therefore, the ‘4XXXX’ reference is implicit. Example: 3-41 Ramp 1 up time is address as holding register 3410. In the message field of the telegram it will be addressed as register 2809 (D51 Hex).

4.1.14

The Coil 65 decimal determines whether data written to the frequency converter are stored in EEPROM and RAM (coil 65=1) or only in RAM (coil 65=0).

Storage of Data

NOTE

Coil 65 needs to be set On before changed parameters are stored in EEPROM and after a Power cycle coil 65 is set back to default Off, meaning only in RAM.

4.1.15 IND

The array index is set in holding register 9 and used when accessing array parameters. Some parameters like 8-43 PCD read configuration have structures of an index and the Modbus protocol does not support index parameters in the telegram frame. To read or write to those parameters requires that register 009 Parameter index contains the index number, before a read or write is done. Example: Setup 8-43 PCD Read Configuration index 2 to the value [1613] Frequency.

1. Write [2] to register 009 Parameter index

2. Write [1613] to holding register 8430

3. Write [0] to register 009 Parameter index to set it back to default 0

Notice after a power cycle register 009 Parameter index is set it back to default 0.

4.1.16

Parameters stored as text strings are accessed in the same way as the other parameters. The maximum text block size is 20 characters. If a read request for a parameter is for more characters than the parameter stores, the response is truncated. If the read request for a parameter is for fewer

Text Blocks

16 MG92B102 - VLT® is a registered Danfoss trademark

Modbus RTU Message Framing ... Modbus RTU Operating Instruction

characters than the parameter stores, the response is space filled.

NOTE

Text blocks are only used together with Function code 11 hex Report slave ID.

4.1.17 Conversion Factor

Since a parameter value can only be transferred as a whole number, a conversion factor must be used to transfer decimals. The conversion index for each parameter can be found in the Programming guide. Example: 4-12 Motor Speed Low Limit [Hz] has a conversion factor of 0.1. To set the Motor Speed Low Limit frequency to 10 Hz, transfer the value 100. A conversion factor of 0.1 means that the value transferred is multiplied by 0.1. The value 100 is thus perceived as 10.0.

Conversion index Conversion factor 100 75 74 67 6 1000000 5 100000 4 10000 3 1000 2 100 1 10 0 1

-1 0.1

-2 0.01

-3 0.001

-4 0.0001

-5 0.00001

-6 0.000001

-7 0.0000001

UNSIGNED32 and SIGNED32 An unsigned and signed integer of 4 bytes fills two registers with the following byte mapping.

Byte 3 Byte 2 Byte 1 Byte 0

Example: Register Address: 40201–Value 0x0102 Register Address: 40202–Value 0x0304

A read of an UNSIGNED32/SIGNED32 from Modbus register 40201 with the quantity of 2, is: 0x01020304.

UNSIGNED16 and SIGNED16 An unsigned and signed integer of 2 bytes fills one register with the following byte mapping.

Byte 1 Byte 0

Example: Register Address: 40201–Value 0x0102

A read of an UNSIGNED16 from register 40201 with the quantity of 1, is: 0x0102.

UNSIGNED8 and SIGNED8 An unsigned and signed integer of 1 byte fills one register with the following byte mapping.

0x00 Byte 0

The data type for each parameter can be found in the Programming guide.

4 4

Table 4.6 Conversion Table

4.1.18

Parameter Values

One Modbus holding register is specified as a 16 bit register, i.e. the data range goes from 0–65535. Some parameters in the frequency converterhave data types of 32 bit, so to be able the read or write to these parameters two registers need to be accessed to have the correct data value read or written.

In order to read and write the different supported data types, the following conversions must be used.

MG92B102 - VLT® is a registered Danfoss trademark 17

How to Control the Frequenc... Modbus RTU Operating Instruction

5 How to Control the Frequency Converter

5.1 How to Control the Frequency Converter

Modbus RTU provides access to control the frequency converter via the Control Word like start/stop and to control the speed of the frequency converter via a bus reference. In the same way it also provides information of

Control Method Address Function Code (hex)

Coils

1-16 Control word 05 Write single coil 17-32 Reference 0F Write Multiple coils 33-48 Status word 49-64 Main Actual Value

65 Parameter Write Control

50000 Control Word 50010 Reference 50200 Status word 50210 Main Actual Value 2810 Control word 2811 Reference 2812-2873 2910 Status word 2911 Main Actual Value 2912-2973

the frequency converter status like running, alarm etc. via the Status Word and the Main Actual Value, i.e. the actual running speed.

01 Read coils

05 Write single coil 01 Read coils

06 Write single register

03 Read holding register

06 Write single register 0F Write Multiple register

03 Read holding register

NOTE

Danfoss recommends only using one of the three mentioned ways to control the frequency converter!

NOTE

Danfoss recommends register 2810-2873 and 2910-2973 to control the frequency converter ensuring compatibility with all controllers.

5.2 Parameter for Modbus RTU

5.2.1 Important Parameters for Modbus RTU

Set the following parameters to enable the Modbus RTU for the frequency converter.

Parameter no. Setting

8-30 Protocol 8-31 Address 8-32 FC Port Baud Rate 8-33 Parity / Stop Bits

Modbus RTU [2] 1-247 2400-19200 Even parity, 1 Stop Bit [0] default Odd Parity, 1 Stop Bit [1] No Parity, 1 Stop Bit [2] No Parity, 1 Stop Bits [3]

NOTE

8-32 FC Port Baud Rate and 8-33 Parity / Stop Bits should match the setting on the controller and other slaves on the network.

Other important parameters to setup are how the control of the frequency converter should be established and what should happen with the motor control in case of bus time out.

See also 8 Parameters.

5.2.2 Access via PCD write/read

The advantage of using the PCD write/read configuration is that the controller can write or read more data in one telegram. Up to 63 registers can be read or written to via the Function code Read Holding register or Write Multiple Registers in one telegram. The structure is also flexible so that only two registers can be written to and 10 registers can be read from the controller.

The PCD write list is data send from the controller to the frequency converter like Control word, Reference and application dependent data like Minimum reference and Ramp times.

18 MG92B102 - VLT® is a registered Danfoss trademark

CTW

Holding Register

2810

Write

Master Frequency Converter

Read

Frequency Converter Master

Controlled by Parameter

Holding Register

Controlled by Parameter

8-42 [0]

REF

2811

8-42 [1]

2812

8-42 [2]

PCD 2

write

2813

8-42 [3]

PCD 3

write

2814

8-42 [4]

PCD 4

write

2815

8-42 [5]

PCD 5

write

...

write

2873

8-42 [63]

PCD 63

write

STW

2910

8-43 [0]

MAV

2911

8-43 [1]

2912

8-43 [2]

PCD 2

read

2913

8-43 [3]

PCD 3

read

2914

8-43 [4]

PCD 4

read

2915

8-43 [5]

PCD 5

read

...

read

2919

8-43 [63]

PCD 63

read

130BC048.10

CTW

REF

Analog output 42

Torque limit

2811

2812

2813

Write

Frequency Converter Drive

CTW = Parameter 16-85, Analog output = Parameter 6-52,

REF = Parameter 16-86, Torque limit Motor mode = 4-16

130BC049.10

Motor current

Digital inputs

Actual Torque [Nm]

2911

2912

2913

2914

Read

Frequency Converter Master

STW

MAV

130BC050.10

STW = Parameter 16-03, Motor Current = Parameter 16-14, Actual Torque [Nm]

MAV = Parameter 16-05, Digital Inputs = Parameter 16-60

130BC198.10

130BC199.10

How to Control the Frequenc... Modbus RTU Operating Instruction

NOTE

The Control word and Reference is always sent in the list from the controller to the frequency converter.

The PCD write list is setup in 8-42 PCD write configuration.

The PCD read list is data send from the frequency converter to the controller like Status word, Main Actual Value and application dependent data like Running Hours, Motor current and Alarm word.

Example: The frequency converter sends status word, main actual value, actual motor current, digital inputs and torque [Nm]

NOTE

The Status word and Main Actual Value is always sent in the list from the frequency converter to the Controller.

NOTE

The boxes marked in grey are not changeable, they are the default values.

5 5

Example, continued The input and output data of the Modbus RTU has to be mapped to the Parameter of the frequency converter. This is done in 8-42 PCD write configuration and 8-43 PCD read configuration.

NOTE

Grey lines are fixed, red are user selectable.

Following parameters has to be set up in the frequency converter:

NOTE

32 bit parameters must be mapped inside the 32 bit boundaries, (PCD2 & PCD3 or PCD4 & PCD5 etc.) where the parameter number is mapped twice to8-42 PCD write configuration or 8-43 PCD read configuration.

5.2.3 Mapping the Holding Registers to Drive Parameters

Example: The PLC sends control word, reference, set the analog output 42 and set the torque limit

NOTE

The motor current in 16-14 Motor Current is 32 bit. This mapping is only mapping the lower 16 bit, so the maximum motor current readout is 327 Amps.

For higher Amp readout, user 32 bit readout.

MG92B102 - VLT® is a registered Danfoss trademark 19

CTW

REF

Ramp 1 Ramp up Time

2811

2812

2813

Write

Master Frequency Converter

CTW = Parameter 16-85, Ramp 1 Ramp up time 3-41,

REF = Parameter 16-86,

130BC053.10

Ramp 1 Ramp up Time

Motor current

Digital inputs

2911

2912

2913

2914

Read

Frequency Converter Master

STW

MAV

130BC054.10

STW = Parameter 16-03, Motor Current = Parameter 16-14,

MAV = Parameter 16-05, Digital Inputs = Parameter 16-60

Motor current

130BC200.10

How to Control the Frequenc... Modbus RTU Operating Instruction

Mapping a 32 bit parameter as 16 bit always accesses the 16 lower bits.

5.2.4 Mapping the Holding Registers to Drive Parameters, 32 bits

Example: The PLC sends control word, reference and Ramp 1 Ramp up Time

Example: The frequency converter sends status word, main actual value, actual motor current and digital inputs

Example 32 bit, continued Following parameters has to be set up in the frequency converter:

NOTE

The motor current in parameter 16-14 is mapped as 32 bit. Motor current can be readout up to 42949672 Amps.

20 MG92B102 - VLT® is a registered Danfoss trademark

Function Code Examples Modbus RTU Operating Instruction

6 Function Code Examples

NOTE

6.1 Examples

The following examples illustrate various Modbus RTU commands. If an error occurs, refer to 9.1.1 Modbus Exception Codes.

Coils and registers are addressed explicit with an off-set of

-1 in Modbus. I.e. Coil 33 is addressed as Coil 32.

6.1.2 Force/Write Single Coil (05 HEX)

6.1.1 Read Coil Status (01 HEX)

Description This function reads the ON/OFF status of discrete outputs (coils) in the frequency converter. Broadcast is never supported for reads.

Query The query message specifies the starting coil and quantity of coils to be read. Coil addresses start at zero, i.e. coil 33 is addressed as 32.

Example of a request to read coils 33-48 (Status Word) from slave device 01.

Field Name Example (HEX) Slave Address 01 (frequency converter address) Function 01 (read coils) Starting Address HI 00 Starting Address LO 20 (32 decimals) Coil 33 No. of Points HI 00 No. of Points LO 10 (16 decimals) Error Check (CRC) -

Response The coil status in the response message is packed as one coil per bit of the data field. Status is indicated as: 1 = ON; 0 = OFF. The LSB of the first data byte contains the coil addressed in the query. The other coils follow toward the high order end of this byte, and from ‘low order to high order’ in subsequent bytes. If the returned coil quantity is not a multiple of eight, the remaining bits in the final data byte will be padded with zeros (toward the high order end of the byte). The Byte Count field specifies the number of complete bytes of data.

Field Name Slave Address 01 (frequency converter address) Function 01 (read coils) Byte Count 02 (2 bytes of data) Data (Coils 40-33) 07 Data (Coils 48-41) 06 (STW=0607hex) Error Check (CRC) -

Example (HEX)

Description This function forces the coil to either ON or OFF. When broadcast the function forces the same coil references in all attached slaves.

Query The query message specifies the coil 65 (parameter write control) to be forced. Coil addresses start at zero, i.e. coil 65 is addressed as 64. Force Data = 00 00HEX (OFF) or FF 00HEX (ON).

Field Name Example (HEX) Slave Address 01 (frequency converter address) Function 05 (write single coil) Coil Address HI 00 Coil Address LO 40 (64 decimal) Coil 65 Force Data HI FF Force Data LO 00 (FF 00 = ON) Error Check (CRC) -

Response The normal response is an echo of the query, returned after the coil state has been forced.

Field Name Slave Address 01 Function 05 Force Data HI FF Force Data LO 00 Quantity of Coils HI 00 Quantity of Coils LO 01 Error Check (CRC) -

Example (HEX)

6.1.3 Force/Write Multiple Coils (0F HEX)

This function forces each coil in a sequence of coils to either ON or OFF. When broadcast the function forces the same coil references in all attached slaves.

The query message specifies the coils 17 to 32 (speed setpoint) to be forced.

MG92B102 - VLT® is a registered Danfoss trademark 21

Function Code Examples Modbus RTU Operating Instruction

NOTE

Coil addresses start at zero, i.e. coil 17 is addressed as 16.

Field Name Example (HEX) Slave Address 01 (frequency converter address) Function 0F (write multiple coils) Coil Address HI 00 Coil Address LO 10 (coil address 17) Quantity of Coils HI 00 Quantity of Coils LO 10 (16 coils) Byte Count 02 Force Data HI (Coils 8-1) Force Data LO (Coils 16-9) Error Check (CRC) -

Response The normal response returns the slave address, function code, starting address, and quantity of coils forced.

6.1.4 Read Holding Registers (03 HEX)

Description This function reads the contents of holding registers in the slave.

Query The query message specifies the starting register and quantity of registers to be read. Register addresses start at zero, i.e. registers 1-4 are addressed as 0-3.

Example: Read 3-03 Maximum Reference, register 03030.

00 (ref. = 2000 hex)

Response The register data in the response message are packed as two bytes per register, with the binary contents right justified within each byte. For each register, the first byte contains the high order bits and the second contains the low order bits.

Example: Hex 0016E360=1.500.000=1500 RPM.

Field Name Example (HEX) Slave Address 01 Function 03 Byte Count 04 Data HI (Register 3030) Data LO (Register 3030) Data HI (Register 3031) Data LO (Register 3031) Error Check (CRC)

6.1.5 Preset Single Register (06 HEX)

Description This function presets a value into a single holding register.

Query The query message specifies the register reference to be preset. Register addresses start at zero, i.e. register 1 is addressed as 0.

Example: Write to 1-00 Configuration Mode, register 1000.

Field Name Slave Address 01 Function 06 Register Address HI 03 (Register address 999) Register Address LO E7 (Register address 999) Preset Data HI 00 Preset Data LO 01 Error Check (CRC) -

Example (HEX)

Field Name Slave Address 01 Function 03 (read holding registers) Starting Address HI 0B (Register address 3029) Starting Address LO D5 (Register address 3029) No. of Points HI 00 No. of Points LO 02 - (Par. 3-03 is 32 bits long, i.e.

Error Check (CRC) -

22 MG92B102 - VLT® is a registered Danfoss trademark

Example (HEX)

2 registers)

Response The normal response is an echo of the query, returned after the register contents have been passed.

Function Code Examples Modbus RTU Operating Instruction

Field Name Example (HEX) Slave Address 01 Function 06 Register Address HI 03 Register Address LO E7 Preset Data HI 00 Preset Data LO 01 Error Check (CRC) -

6.1.6 Preset Multiple Registers (10 HEX)

Description This function presets values into a sequence of holding registers.

Query The query message specifies the register references to be preset. Register addresses start at zero, i.e. register 1 is addressed as 0. Example of a request to preset two registers (set parameter 1-24=738 (7.38 A)):

Field Name Example (HEX) Slave Address 01 Function 10 Starting Address HI 04 Starting Address LO D7 No. of Registers HI 00 No. of registers LO 02 Byte Count 04 Write Data HI (Register 4: 1049) Write Data LO (Register 4: 1049) Write Data HI (Register 4: 1050) Write Data LO (Register 4: 1050) Error Check (CRC) -

Response The normal response returns the slave address, function code, starting address, and quantity of registers preset.

Field Name Slave Address 01 Function 10 Starting Address HI 04 Starting Address LO D7 No. of Registers HI 00 No. of registers LO 02 Error Check (CRC) -

Example (HEX)

MG92B102 - VLT® is a registered Danfoss trademark 23

Speed ref.CTW

Master-slave

130BA274.10

15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

Bit no.:

FC Control Profile Modbus RTU Operating Instruction

7 FC Control Profile

7.1.1 Control Word According to FC Profile (8-10 Protocol = FC profile)

Bit 02, DC brake Bit 02 = ’0’ leads to DC braking and stop. Set braking current and duration in 2-01 DC Brake Current and 2-02 DC Braking Time. Bit 02 = ’1’ leads to ramping.

Bit 03, Coasting Bit 03 = ’0’: The frequency converter immediately "lets go" of the motor, (the output transistors are "shut off") and it coasts to a standstill.

Bit Bit value = 0 Bit value = 1 00 Reference value external selection lsb 01 Reference value external selection msb 02 DC brake Ramp

03 Coasting No coasting 04 Quick stop Ramp 05 Hold output

frequency 06 Ramp stop Start 07 No function Reset 08 No function Jog 09 Ramp 1 Ramp 2 10 Data invalid Data valid 11 Relay 01 open Relay 01 active 12 Relay 02 open Relay 02 active 13 Parameter set-up selection lsb 15 No function Reverse

use ramp

Bit 03 = ’1’: The frequency converter starts the motor if the other starting conditions are met.

Make a selection in 8-50 Coasting Select to define how Bit 03 gates with the corresponding function on a digital input.

Bit 04, Quick stop Bit 04 = ’0’: Makes the motor speed ramp down to stop (set in 3-81 Quick Stop Ramp Time).

Bit 05, Hold output frequency Bit 05 = ’0’: The present output frequency (in Hz) freezes. Change the frozen output frequency only with the digital inputs (5-10 Terminal 18 Digital Input to 5-13 Terminal 29

Digital Input) programmed to Speed up = 21 and Slow down = 22.

Explanation of the Control Bits

Bits 00/01 Bits 00 and 01 are used to choose between the four reference values, which are pre-programmed in 3-10 Preset Reference according to the Table 7.1.

Programmed ref. value 1 2 3 4

Table 7.1 Control bits

NOTE

Make a selection in 8-56 Preset Reference Select to define how Bit 00/01 gates with the corresponding function on the digital inputs.

24 MG92B102 - VLT® is a registered Danfoss trademark

Parameter Bit 01 Bit 00

3-10 Preset Reference [0] 3-10 Preset Reference [1] 3-10 Preset Reference [2] 3-10 Preset Reference [3]

0 0 0 1 1 0 1 1

NOTE

If Freeze output is active, the frequency converter can only be stopped by the following:

Bit 03 Coasting stop

•

Bit 02 DC braking

•

Digital input (5-10 Terminal 18 Digital Input to

•

5-13 Terminal 29 Digital Input) programmed to DC braking = 5, Coasting stop = 2, or Reset and coasting stop = 3.

06, Ramp stop/start

Bit Bit 06 = ’0’: Causes a stop and makes the motor speed ramp down to stop via the selected ramp down parameter. Bit 06 = ’1’: Permits the frequency converter to start the motor, if the other starting conditions are met.

Make a selection in 8-53 Start Select to define how Bit 06 Ramp stop/start gates with the corresponding function on a digital input.

Output freq.STW

Bit no.:

Slave-master

15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

130BA273.10

FC Control Profile Modbus RTU Operating Instruction

Bit 07, Reset Bit 07 = ’0’: No reset. Bit 07 = ’1’: Resets a trip. Reset is activated on the signal’s leading edge, i.e. when changing from logic ’0’ to logic ’1’.

Bit 08, Jog Bit 08 = ’1’: The output frequency is determined by 3-11 Jog Speed [Hz].

Bit 09, Selection of ramp 1/2 Bit 09 = "0": Ramp 1 is active (3-41 Ramp 1 Ramp up Time to 3-42 Ramp 1 Ramp Down Time). Bit 09 = "1": Ramp 2 (3-51 Ramp 2 Ramp up Time to 3-52 Ramp 2 Ramp down Time) is active.

Bit 10, Data not valid/Data valid Tell the frequency converter whether to use or ignore the control word. Bit 10 = ’0’: The control word is ignored. Bit 10 = ’1’: The control word is used. This function is relevant because the telegram always contains the control word, regardless of the telegram type. Turn off the control word if not wanting to use it when updating or reading parameters.

Bit 11, Relay 01 Bit 11 = "0": Relay not activated. Bit 11 = "1": Relay 01 activated provided that Control word bit 11 = 36 is chosen in 5-40 Function Relay.

Bit 12, Relay 02 Bit 12 = "0": Relay 02 is not activated. Bit 12 = "1": Relay 02 is activated provided that Control word bit 12 = 37 is chosen in 5-40 Function Relay.

Bit 13, Selection of set-up Use bit 13 to choose from the 2 menu set-ups according to the table.

Set-up

1 0 2 1

Bit 13

7.1.2

Status Word According to FC Profile (STW) (8-30 Protocol = FC profile)

Bit Bit = 0 Bit = 1 00 Control not ready Control ready 01 Drive not ready Drive ready 02 Coasting Enable 03 No error Trip 04 No error Error (no trip) 05 Reserved 06 No error Triplock 07 No warning Warning 08 09 Local operation Bus control 10 Out of frequency limit Frequency limit OK 11 No operation In operation 12 Drive OK Stopped, auto start 13 Voltage OK Voltage exceeded 14 Torque OK Torque exceeded 15 Timer OK Timer exceeded

Speed ≠ reference

Explanation of the Status Bits Bit 00, Control not ready/ready Bit 00 = ’0’: The frequency converter trips. Bit 00 = ’1’: The frequency converter controls are ready but the power component does not necessarily receive any power supply (in case of external 24 V supply to controls).

Bit 01, Drive ready Bit 01 = ’1’: The frequency converter is ready for operation but the coasting command is active via the digital inputs or via serial communication.

Speed = reference

7 7

The function is only possible when Multi Set-Ups = 9 is selected in 0-10 Active Set-up.

Make a selection in 8-55 Set-up Select to define how Bit 13 gates with the corresponding function on the digital inputs.

Bit 15 Reverse Bit 15 = ’0’: No reversing. Bit 15 = ’1’: Reversing. In the default setting, reversing is set to digital in 8-54 Reversing Select. Bit 15 causes reversing only when Ser. communication, Logic or Logic and is selected.

Bit 02, Coasting stop Bit 02 = ’0’: The frequency converter releases the motor. Bit 02 = ’1’: The frequency converter starts the motor with a start command.

Bit 03, No error/trip Bit 03 = ’0’ : The frequency converter is not in fault mode. Bit 03 = ’1’: The frequency converter trips. To re-establish operation, press [Reset].

Bit 04, No error/error (no trip) Bit 04 = ’0’: The frequency converter is not in fault mode. Bit 04 = “1”: The frequency converter shows an error but does not trip.

MG92B102 - VLT® is a registered Danfoss trademark 25

Actual output freq.

STW

Slave-master

Speed ref.CTW

Master-slave

16bit

130BA276.10

FC Control Profile Modbus RTU Operating Instruction

Bit 05, Not used Bit 05 is not used in the status word.

Bit 12 = ’1’: The inverter stops because of over temperature but the unit does not trip and will resume operation once the over temperature stops.

Bit 06, No error / triplock Bit 06 = ’0’: The frequency converter is not in fault mode. Bit 06 = “1”: The frequency converter is tripped and locked.

Bit 13, Voltage OK/limit exceeded Bit 13 = ’0’: There are no voltage warnings. Bit 13 = ’1’: The DC voltage in the frequency converter’s

Bit 07, No warning/warning

intermediate circuit is too low or too high.

Bit 07 = ’0’: There are no warnings. Bit 07 = ’1’: A warning has occurred.

Bit 14, Torque OK/limit exceeded Bit 14 = ’0’: The motor current is lower than the torque

Bit 08, Speed≠ reference/speed = reference Bit 08 = ’0’: The motor is running but the present speed is different from the preset speed reference. It might e.g. be

limit selected in 4-18 Current Limit. Bit 14 = ’1’: The torque limit in 4-18 Current Limit is exceeded.

the case when the speed ramps up/down during start/ stop. Bit 08 = ’1’: The motor speed matches the preset speed reference.

Bit 15, Timer OK/limit exceeded Bit 15 = ’0’: The timers for motor thermal protection and thermal protection are not exceeded 100%. Bit 15 = ’1’: One of the timers exceeds 100%.

Bit 09, Local operation/bus control Bit 09 = ’0’: [Off/Reset] is activate on the control unit or

Bus Speed Reference Value

7.1.3

Local control in F-02 Operation Method is selected. It is not possible to control the frequency converter via serial communication. Bit 09 = ’1’ It is possible to control the frequency converter via the fieldbus/serial communication.

Speed reference value is transmitted to the frequency converter in a relative value in %. The value is transmitted in the form of a 16-bit word; in integers (0-32767) the value 16384 (4000 Hex) corresponds to 100%. Negative

figures are formatted by means of 2’s complement. The Bit 10, Out of frequency limit Bit 10 = ’0’: The output frequency has reached the value in

Actual Output frequency (MAV) is scaled in the same way

as the bus reference.

4-12 Motor Speed Low Limit [Hz] or 4-14 Motor Speed High Limit [Hz].

Bit 10 = "1": The output frequency is within the defined limits.

Bit 11, No operation/in operation Bit 11 = ’0’: The motor is not running. Bit 11 = ’1’: The frequency converter has a start signal or the output frequency is greater than 0 Hz.

Bit 12, Drive OK/stopped, autostart: Bit 12 = ’0’: There is no temporary over temperature on the inverter.

The reference and MAV are scaled as follows:

26 MG92B102 - VLT® is a registered Danfoss trademark

Reverse Forward

Par.3-00 set to

(1) -max- +max

Max reference Max reference

Par.3-00 set to

(0) min-max

Max reference

Forward

Min reference

100%

(4000hex)

-100%

(C000hex)

(0hex)

Par.3-03 0 Par.3-03

Par.3-03

(4000hex)(0hex)

0% 100%

Par.3-02

130BA277.10

FC Control Profile Modbus RTU Operating Instruction

7 7

MG92B102 - VLT® is a registered Danfoss trademark 27

Parameters Modbus RTU Operating Instruction

8 Parameters

8-03 Control Word Timeout Time

8.1 Parameters: 8-** Communications and

Options

8.1.1 8-0* General Settings

8-01 Control Site

Option: Function:

The setting in this parameter overrides the settings in 8-50 Coasting Select to 8-56 Preset Reference Select.

[0] * Digital and

ctrl.word

[1] Digital only Control by using digital inputs only.

[2] Controlword only Control by using control word only.

Control by using both digital input and control word.

8-02 Control Word Source

Select the source of the control word: one of two serial interfaces or four installed options. During initial power-up, the frequency converter automatically sets this parameter to [3] Option A if it detects a valid Fieldbus option installed in slot A. If the option is removed, the frequency converter detects a change in the configuration, sets 8-02 Control Word Source back to default setting RS-485, and the frequency converter trips. If an option is installed after initial power-up, the setting of 8-02 Control Word Source does not change, but the frequency converter trips and displays: Alarm 67 Option Changed. When retrofitting a bus option into a frequency converter, that did not have a bus option installed to begin with, take an ACTIVE decision to move the control to Bus based. This is done for safety reasons in order to avoid an accidental change.

Option: Function:

[0] None [1] * FC RS485 [2] FC USB [3] Option A [4] Option B [5] Option C0 [6] Option C1 [30] External Can

NOTE

This parameter cannot be adjusted while the motor is running.

Range: Function:

1.0 s* [Application dependant]

Enter the maximum time expected to pass between the reception of two consecutive telegrams. If this time is exceeded, it indicates that the serial communication has stopped. The function selected in 8-04 Control Word Timeout Functionis then carried out. A valid control word triggers the time-out counter.

8-04 Control Word Timeout Function

Select the time-out function. The time-out function activates when the control word fails to be updated within the time period specified in 8-03 Control Word Timeout Time.

Option: Function:

[0] * Off Resumes control via serial bus (Fieldbus or

standard) using the most recent control word.

[1] Freeze output Freezes output frequency until communi-

cation resumes.

[2] Stop Stops with auto restart when communi-

cation resumes.

[3] Jogging Runs the motor at JOG frequency until

communication resumes.

[4] Max. speed Runs the motor at maximum frequency

until communication resumes.

[5] Stop and trip Stops the motor, then resets the frequency

converter to restart: via the Fieldbus, via the reset button on the , or via a digital input.

[7] Select setup 1 Changes the set-up upon reestablishment of

communication following a control word time-out. If communication resumes after a time-out, 8-05 End-of-Timeout Function defines whether to resume the set-up used before the time-out, or to retain the set-up endorsed by the time-out function.

[8] Select setup 2

[9] Select setup 3

[10] Select setup 4

[26] Trip

See [7] Select setup 1

NOTE

To change the set-up after a time-out, the following configuration is required: Set 0-10 Active Set-up to [9] Multi set-up and select the relevant link in 0-12 This Set-up Linked to.

28 MG92B102 - VLT® is a registered Danfoss trademark

Parameters Modbus RTU Operating Instruction

8-05 End-of-Timeout Function

Option: Function:

Select the action after receiving a valid control word following a time-out. This parameter is active only when 8-04 Control Timeout Function is set to [Set-up 1-4].

[0] Hold set-up

[1] * Resume set-upResumes the set-up active before the time-

Retains the set-up selected in 8-04 Control Timeout Function and displays a warning, until 8-06 Reset Control Timeout toggles. Then the frequency converter resumes its original set-up.

out.

8-06 Reset Control Word Timeout

This parameter is active only when [0] Hold set-up has been selected in 8-05 End-of-Timeout Function.

Option: Function:

[0] * Do not reset

[1] Do reset Returns the frequency converter to the

Retains the set-up specified in 8-04 Control Word Timeout Function, following a control word time-out.

original set-up following a control word timeout. The frequency converter performs the reset and then immediately reverts to the [0] Do not reset setting

8-08 Readout Filtering

If the speed feedback value readouts on fieldbus are fluctuating, this function is used. Select filtered if the function is required. A power-cycle is required for changes to take effect.

Option: Function:

[0] * Motor Data Std-

Filt.

[1] Motor Data LP-

Filter

Select [0] for normal bus readouts.

Select [1] for filtered bus readouts of the following parameters:

16-10 Power [kW] 16-11 Power [hp] 16-12 Motor Voltage 16-14 Motor Current 16-16 Torque [Nm] 16-17 Speed [RPM] 16-22 Torque [%] 16-25 Torque [Nm] High

8.1.2 8-1* Ctrl. Word Settings

8-10 Control Word Profile

Select the interpretation of the control and status words corresponding to the installed Fieldbus. Only the selections valid for the Fieldbus installed in slot A will be visible in the display. For guidelines in selection of [0] FC profile and [1] PROFIdrive profile refer to Serial communication via RS 485 Interface section. For additional guidelines in the selection of [1] PROFIdrive profile, [5] ODVA and [7] CANopen DSP 402 , see Operating Instructions for the installed Fieldbus.

Option: Function:

[0] * FC profile [1] PROFIdrive profile [5] ODVA [7] CANopen DSP 402 [8] MCO

8-13 Configurable Status Word STW

Option: Function:

[0] No function The input is always low.

[1] * Profile Default Depended on the profile set in

8-10 Control Profile.

[2] Alarm 68 Only The input goes high whenever Alarm 68

is active and goes low whenever no alarm 68 is actived

[3] Trip excl Alarm68The input goes high whenever Trip on

other Alarms then Alarm 68 is active.

[10] T18 DI status The input goes high whenever T18 has 24

V and goes low whenever T18 has 0 V

[11] T19 DI status The input goes high whenever T19 has 24

V and goes low whenever T19 has 0 V

[12] T27 DI status The input goes high whenever T27 has 24

V and goes low whenever T27 has 0 V

[13] T29 DI status The input goes high whenever T29 has 24

V and goes low whenever T29 has 0 V

[14] T32 DI status The input goes high whenever T32 has 24

V and goes low whenever T32 has 0 V

[15] T33 DI status The input goes high whenever T33 has 24

V and goes low whenever T33 has 0 V

[16] T37 DI status The input goes high whenever T37 has 0

V and goes low whenever T37 has 24 V

[21] Thermal

warning

[30] Brake fault

(IGBT)

[40] Out of ref

range

The thermal warning turns on when the temperature exceeds the limit in the motor, the frequency converter, the brake resistor, or the thermistor.

Goes high when the brake IGBT is shortcircuited.

If Comparator 0 is evaluated as TRUE, the input goes high. Otherwise, it will be low.

8 8

MG92B102 - VLT® is a registered Danfoss trademark 29

Parameters Modbus RTU Operating Instruction

8-13 Configurable Status Word STW

Option: Function:

[60] Comparator 0 If Comparator 0 is evaluated as TRUE, the