Danfoss vacon 20, vacon 20 x, vacon 20 cp User guide

VACON® 20 VACON® 20 X

VACON® 20 CP

AC DRIVES

MODBUS RTU USER MANUAL

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		Table of Contents
		Document: DPD01925A
		Version release date: 30.5.17
1.		Safety................................................................................................................	2
1.1		Danger.................................................................................................................................	2
1.2		Warnings .............................................................................................................................	3
1.3		Earthing and earth fault protection....................................................................................	4
2.		Modbus - general info.......................................................................................	5
2.1		Restrictions.........................................................................................................................	6
3.		Modbus technical data ......................................................................................	7
3.1		Modbus RTU protocol .........................................................................................................	7
3.2		Connections and wiring ......................................................................................................	7
4.		Installation........................................................................................................	8
4.1		Installation in VACON® 20 family AC drives ......................................................................	8
4.1.1		Preparation for use through RS485....................................................................................	8
5.		Fieldbus parametrization ...............................................................................	10
5.1		Fieldbus control and basic reference selection...............................................................	10
5.2		Modbus RTU parameters and monitoring values ............................................................	10
5.2.1		Fieldbus protocol ..............................................................................................................	11
5.2.2		Slave address....................................................................................................................	11
5.2.3		Baud rate...........................................................................................................................	11
5.2.4		Parity type .........................................................................................................................	12
5.2.5		Communication timeout ...................................................................................................	12
5.2.6		Reset communication status............................................................................................	12
5.2.7		Communication status......................................................................................................	12
6.		Communications.............................................................................................	13
6.1		Modbus address area .......................................................................................................	13
6.2		Supported Modbus Functions...........................................................................................	13
6.3		Modbus data mapping.......................................................................................................	14
6.3.1		Modbus process data in VACON® 20 Application ACCN1004..........................................	14
6.3.2		Modbus process data in VACON® 20X and VACON® CP Application ACIT1075 .............	17
6.4		Example messages...........................................................................................................	20
6.4.1		Example 1 - Write Process Data.......................................................................................	20
6.4.2		Example 2 - Read process data........................................................................................	21
7.		Fault tracing ...................................................................................................	22
7.1		Typical fault conditions .....................................................................................................	22
7.2		RS-485 bus biasing ...........................................................................................................	22
7.3		Other fault conditions .......................................................................................................	23
8.		Quick setup .....................................................................................................	24
9.	APPENDIX 1 - PROCESS DATA ........................................................................		25

Local contacts: http://drives.danfoss.com/danfoss-drives/local-contacts/

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Safety

1.SAFETY

This manual contains clearly marked cautions and warnings which are intended for your personal safety and to avoid any unintentional damage to the product or connected appliances.

Please read the information included in cautions and warnings carefully.

The cautions and warnings are marked as follows:

Table 1. Warning signs

= DANGER! Dangerous voltage

9000.emf

= WARNING or CAUTION

13006.emf

= Caution! Hot surface

9001.emf

1.1Danger

The components of the power unit are live when the drive is connected to mains potential. Coming into contact with this voltage is extremely dangerous and may cause death or severe injury.

The motor terminals U, V, W and the brake resistor terminals are live when the AC drive is connected to mains, even if the motor is not running.

After disconnecting the AC drive from the mains, wait until the indicators on the keypad go out (if no keypad is attached see the indicators on the cover). Wait 5 more minutes before doing any work on the connections of the drive. Do not open the cover before this time has expired. After expiration of this time, use a measuring equipment to absolutely ensure that no voltage is present. Always ensure absence of voltage before starting any electrical work!

The control I/O-terminals are isolated from the mains potential. However, the relay outputs and other I/O-terminals may have a dangerous control voltage present even when the AC drive is disconnected from mains.

Before connecting the AC drive to mains make sure that the front and cable covers of the drive are closed.

During a ramp stop (see the Application Manual), the motor is still generating voltage to the drive. Therefore, do not touch the components of the AC drive before the motor has completely stopped. Wait until the indicators on the keypad go out (if no keypad is attached see the indicators on the cover). Wait additional 5 minutes before starting any work on the drive.

1	Local contacts: http://drives.danfoss.com/danfoss-drives/local-contacts/

Safety

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1.2Warnings

The AC drive is meant for fixed installations only.

Do not perform any measurements when the AC drive is connected to the mains.

The earth leakage current of the AC drives exceeds 3.5mA AC. According to standard EN61800-5-1, a reinforced protective ground connection must be ensured. See chapter 1.3.

If the AC drive is used as a part of a machine, the machine manufacturer is responsible for providing the machine with a supply disconnecting device (EN 60204-1).

Only spare parts delivered by VACON® can be used.

At power-up, power break or fault reset the motor will start immediately if the start signal is active, unless the pulse control for Start/Stop logic has been selected. Futhermore, the I/O functionalities (including start inputs) may change if parameters, applications or software are changed. Disconnect, therefore, the motor if an unexpected start can cause danger.

The motor starts automatically after automatic fault reset if the auto restart function is activated. See the Application Manual for more detailed information.

Prior to measurements on the motor or the motor cable, disconnect the motor cable from the AC drive.

Do not touch the components on the circuit boards. Static voltage discharge may damage the components.

Check that the EMC level of the AC drive corresponds to the requirements of your supply network.

Local contacts: http://drives.danfoss.com/danfoss-drives/local-contacts/

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Safety

1.3Earthing and earth fault protection

CAUTION!

The AC drive must always be earthed with an earthing conductor connected to the earthing terminal marked with .

The earth leakage current of the drive exceeds 3.5mA AC. According to EN61800-5-1, one or more of the following conditions for the associated protective circuit shall be satisfied:

b)The protective conductor shall have a cross-sectional area of at least 10 mm2 Cu or 16 mm2 Al, through its total run.

c)Where the protective conductor has a cross-sectional area of less than 10 mm2 Cu or 16 mm2 Al, a second protective conductor of at least the same cross-sectional area shall be provided up to a point where the protective conductor has a cross-sectional area not less than 10 mm2 Cu or 16 mm2 Al.

d)Automatic disconnection of the supply in case of loss of continuity of the protective conductor.

The cross-sectional area of every protective earthing conductor which does not form part of the supply cable or cable enclosure shall, in any case, be not less than:

-2.5mm2 if mechanical protection is provided or

-4mm2 if mechanical protection is not provided.

The earth fault protection inside the AC drive protects only the drive itself against earth faults in the motor or the motor cable. It is not intended for personal safety.

Due to the high capacitive currents present in the AC drive, fault current protective switches may not function properly.

Do not perform any voltage withstand tests on any part of the AC drive. There is a certain procedure according to which the tests shall be performed. Ignoring this procedure may result in damaged product.

NOTE! You can download the English and French product manuals with applicable safety, warning and caution information from http://drives.danfoss.com/knowledge-center/technical-documentation/.

REMARQUE Vous pouvez télécharger les versions anglaise et française des manuels produit contenant l’ensemble des informations de sécurité, avertissements et mises en garde applicables sur le site http://drives.danfoss.com/knowledge-center/technical-documentation/

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1	Local contacts: http://drives.danfoss.com/danfoss-drives/local-contacts/

Modbus - general info

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2.MODBUS - GENERAL INFO

Modbus is a communication protocol developed by Modicon systems. In simple terms, it is a way of sending information between electronic devices. The device requesting the information is called the Modbus Master and the devices supplying information are Modbus Slaves. The Master can also write information to the Slaves. Modbus is typically used to transmit signals from instrumentation and control devices back to a main controller or data gathering system.

Standard Modbus network contains one Master device and up to 247 Slave devices. In ModbusRTU networks it is mandatory to define a unique Slave Address (or Unit identifier number) for the every Slave Device. Slave Address is a number between 1 and 247. Modbus ASCII mode is not supported.

The Modbus communication interface is built around messages. The format of these Modbus messages is independent of the type of physical interface used. The same protocol can be used regardless of the connection type. Because of this, Modbus gives the possibility to easily upgrade the hardware structure of an industrial network, without the need for large changes in the software. A device can also communicate with several Modbus nodes at once, even if they are connected with different interface types, without the need to use a different protocol for every connection.

Master´s		Slave
message		response
Start		Start
Address		Address
Function		Function
Data		Data
CRC		CRC
End		End

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Figure 1.Basic structure of Modbus frame

On simple interfaces like RS485, the Modbus messages are sent in plain form over the network. In this case the network is dedicated to Modbus.

Each Modbus message has the same structure. Four basic elements are present in each message. The sequence of these elements is the same for all messages, to make it easy to parse the content of the Modbus message. A conversation is always started by a master in the Modbus network. A Modbus master sends a message and—depending of the contents of the message—a slave takes action and responds to it. Addressing in the message header is used to define which device should respond to a message. All other nodes on the Modbus network ignore the message if the address field does not match their own address.

Your VACON® 20 family AC drive is equipped with Modbus support as standard. If you need to contact VACON® service in problems related to Modbus, send a description of the problem together with the Drive Info File taken with VACON® Live to customer support. If possible, also send a "Wireshark" log from the situation if applicable.

Local contacts: http://drives.danfoss.com/danfoss-drives/local-contacts/

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Modbus - general info

Ethernet

Modbus TCP

Switch

Modbus

RTU

master

Modbus RTU

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Figure 2.Principal example diagram of Modbus

2.1Restrictions

When a fieldbus option board or an OPTBH option board has been installed, Modbus is not working.

2	Local contacts: http://drives.danfoss.com/danfoss-drives/local-contacts/

Modbus technical data

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3.MODBUS TECHNICAL DATA

3.1Modbus RTU protocol

Modbus RTU is the only supported transmission mode. Modbus ASCII mode is not supported.

			Table 2.
		Interface	RS-485
		Data transfer method	RS-485 MS/TP, half-duplex
		Transfer cable	STP (Shielded Twisted Pair)
Connections and		Connector	2.5 mm2
		Electrical isolation	Functional
communications
		Modbus RTU	As described in “Modicon Modbus Proto-
			col Reference Guide”
		Bitrate	300, 600, 1200, 2400, 4800, 9600, 19200,
			38400, and 57600 bits/s
		Addresses	1 to 247

3.2Connections and wiring

The maximum length of an RS-485 cable depends on the bitrate used, the cable (gauge, capacitance or characteristic impedance) and the number of devices in the bus. The Modbus RTU specification states that for a maximum 9600 bits/second bitrate and AWG26 or wider gauge, the maximum length is 1000 meters. The actual cable length used in an installation can be lower than this number depending on the aforementioned parameters.

Local contacts: http://drives.danfoss.com/danfoss-drives/local-contacts/

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