Operating instructions

ManualsBrandsDanfoss ManualsMedia ConverterVLT 8000 AQUA

VLT

2800, VLT

6000 HVAC and VLT

8000 AQUA Modbus RTU

■ Contents

Overview

............................................................................................................. 6

Introduction ............................................................................................................ 6

About This Manual ................................................................................................. 6

Assumptions .......................................................................................................... 6

What You Should Already Know ............................................................................. 6

Modbus RTU Overview .......................................................................................... 6

VLT 2800, VLT 6000 and VLT 8000 with Modbus RTU ........................................... 7

Installation and Setup .................................................................................. 8

Network Connection ............................................................................................. 8

Hardware Setup VLT 2800 ..................................................................................... 9

Hardware Setup VLT 6000 and VLT 8000 ............................................................... 9

EMC Precautions ................................................................................................... 9

Modbus RTU Programming ....................................................................... 10

VLT 2800 Parameter Settings for Modbus Communication ..................................... 10

VLT 6000 Parameter Settings for Modbus Communication ..................................... 12

Installation and Set-up VLT 8000 ............................................................................ 13

VLT 8000 Parameter Settings for Modbus Communication ..................................... 13

Network Configuration ................................................................................. 14

Remote Terminal Unit ............................................................................................. 14

Modbus RTU Message Framing Structure .............................................................. 14

Parameter Handling ....................................................................................... 16

Parameter Handling ................................................................................................ 16

Storage of Data ...................................................................................................... 16

Process Data ......................................................................................................... 20

Status Coil Maps .................................................................................................... 20

Control Word Bit Descriptions for VLT 2800 ............................................................ 20

Status Word Bit Description for VLT 2800 ............................................................... 21

Control Word Bit Descriptions VLT 6000 / VLT 8000 ............................................... 23

Status Word Bit Descriptions VLT 6000 / VLT 8000 ................................................ 25

Serial communication reference .............................................................................. 26

Present output frequency ....................................................................................... 26

Supported Modbus RTU Function Codes ......................................... 28

Exception Codes ............................................................................................. 31

Exception Code Tables .......................................................................................... 31

Appendix A - Examples ............................................................................... 32

MG.10.S2.02 - VLT is a registered Danfoss trademark

Summary of content (35 pages)

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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU ■ Contents Overview 6 6 6 6 6 6 7 Installation and Setup 8 8 9 9 9 ............................................................................................................. Introduction ............................................................................................................ About This Manual ................................................................................................. Assumptions ........................
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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU VLT 2800 Series 195NA009.17 ■ Software Version VLT 2800, VLT 6000 and VLT 8000 Operating instructions Software version: 2.8x VLT 6000 HVAC 175ZA691.14 These operating instructions can be used for all VLT 2800 Series frequency converters with software version 2.8x. The software version number can be seen from parameter 640 Software version no. Operating Instructions Software version: 3.
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VLT 8000 AQUA 176FA145.13 VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU Safety - Modbus RTU Operating Instructions Software version: 1.5x These Operating Instructions can be used for all VLT 8000 AQUA frequency converters with software version 1.5x. The software version number can be seen from parameter 624 Software version no. ■ High Voltage Warning Rotating shafts and electrical equipment can be hazardous.
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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU VLT 2800 Warning: It can be extremely dangerous to touch the electrical parts even when the mains supply has been disconnected. Also ensure that other voltage inputs are disconnected from load sharing through the DC bus. Wait at least 4 minutes after the input power has been removed before servicing the drive. 195NA139.10 Warning: Touching the electrical parts may be fatal - even after the equipment has been disconnected from mains. 175HA490.
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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU Warning: 176FA159.12 VLT 8000 AQUA MG.10.S2.02 - VLT is a registered Danfoss trademark Safety - Modbus RTU Touching the electrical parts may be fatal - even after the equipment has been disconnected from line.
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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU ■ Overview ■ Introduction These operating instructions provide comprehensive instructions on the installation and set up of the Modbus RTU for VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Frequency Converter to communicate over a Modbus network. For specific information on installation and operation of the frequency converter, refer to the VLT® 2800 Operating Instructions, MG.28.AX.YY / VLT® 6000 HVAC Operating Instructions, MG.61.AX.
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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU ■ VLT 2800, VLT 6000 and VLT 8000 with Modbus RTU The frequency converter communicates in Modbus RTU format over an EIA-485 (formerly RS-485) network. Modbus RTU allows access to the frequency converter’s Control Word and Bus Reference.
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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU ■ Installation and Setup Modbus RTU is a transmission protocol developed for process control systems. The Modbus standard does not specify the physical interface for the protocol i.e. a number of different interfaces can be chosen. The Modbus RTU protocol is based on the build-in RS-485 (EIA-485) interface. RS-485 is a two-wire bus-interface that allows multi-drop network topology i.e.
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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU ■ Hardware Setup VLT 2800 The VLT 2800 control card does not have build-in termination network for RS 485. To terminate with the ■ Hardware Setup VLT 6000 and VLT 8000 A terminator dip switch on the main control board of the frequency converter is used to terminate the Modbus RTU bus. The switch positions shown in Figure 2 demonstrate the factory setting. Table 1 lists the switch functions and settings required for Modbus RTU operation.
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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU ■ VLT 2800 Parameter Settings for Modbus Communication Using the Modbus RTU Protocol requires setting of the below listed parameters. Description of choice: The frequency converter’s transmission speed must be set at a value corresponding to the transmission speed of the master. Parameter 501 Baudrate cannot be selected via the serial port, but must be preset via the operating unit. NB!: Please make sure that par.
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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU 571 Modbus communications timeout (M.BUS COM.TIME.) Value: 10 ms - 2000 ms ✭ 100 ms Function: This parameter determines the maximum amount of time that the drive’s Modbus RTU will wait between characters that are sent by the master controller. When this amount of time expires, the drive’s Modbus RTU interface will assume that it has received the entire message.
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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU ■ VLT 6000 Parameter Settings for Modbus Communication Using the Modbus RTU Protocol requires setting of the below listed parameters. See the VLT 6000 Operating Instructions MG.61.AX.YY for details on selecting and changing parameter values, if necessary. 500 570 Modbus parity and message framing (M.BUS PAR.
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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU ■ VLT 8000 Parameter Settings for Modbus Communication Using the Modbus RTU Protocol requires setting of the below listed parameters. See the VLT 8000 Operating Instructions MG.80.AX.YY for details on selecting and changing parameter values, if necessary. Description of choice: Protocol (PROTOCOL) Value: ✭FC protocol (FC PROTOCOL) Modbus RTU (MODBUS RTU) [0] [1] Function: There is a choice of two different protocols.
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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU ■ Network Configuration ■ Remote Terminal Unit The controllers are setup to communicate on the Modbus network using RTU (Remote Terminal Unit) mode, with each 8-bit byte in a message contains two 4-bit hexadecimal characters. The format for each byte is shown below.
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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU ■ 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.
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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU ■ Parameter Handling ■ Parameter Handling PNU (Parameter Number) is translated from the register address contained in the Modbus read/write message. The parameter number is translated to Modbus as (10 x parameter number)DECIMAL. ■ Storage of Data Coil 65 decimal determines whether data written to the frequency converter are stored in EEPROM and RAM (coil 65 = 1) or just RAM (coil 65 = 0).
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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU ■ Register Maps VLT 2800 Note: the Holding Register number shown in the following table must be transmitted as ("shown value-1") in MODBUS telegrams (e.g. Holding Register 4:00001 is transmitted as address 0 in MODBUS telegrams).
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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU ■ Register Maps VLT 6000 Note: the Holding Register number shown in the following table must be transmitted as ("shown value-1") in MODBUS telegrams (e.g. Holding Register 4:00001 is transmitted as address 0 in MODBUS telegrams).
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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU ■ Register Maps VLT 8000 Note: the Holding Register number shown in the following table must be transmitted as ("shown value-1") in MODBUS telegrams (e.g. Holding Register 4:00001 is transmitted as address 0 in MODBUS telegrams).
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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU ■ Process Data Process Data is illustrated as coils in Modbus RTU. ■ Status Coil Maps (128 coils total) Note: The coil number shown in the following table must be transmitted as ("shown value-1") in MODBUS telegrams (e.g. Coil number 0:00001 is transmitted as address 0000 in the MODBUS telegram). Coil Number 1-16 17-32 33-48 49-64 65 66-128 ■ Control Word Bit Descriptions for VLT 2800 The control word is used to send commands from a master (e.g.
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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU Bit 05, Freeze output frequency: Bit 05 = ’0’ causes the present output frequency (in Hz) to freeze. The frozen output frequency can now only be changed by means of the digital inputs programmed to Speed up and Speed down. NB!: If Freeze output is active, the frequency converter cannot be stopped via Bit 06 Start or via a digital input.
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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU Bit 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 Bit = 0 Bit =1 Control ready Drive ready Coasting stop No trip Not used Not used No warning Speed ≠ ref. Local control Outside frequency range Trip Trip lock Warning Speed = ref. Ser. communi. Frequency limit OK Motor running Voltage warn. Current limit Thermal warn. Bit 00, Control ready: Bit 00 = ’1’. The frequency converter is ready for operation. Bit 00 = ’0’.
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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU ■ Present output frequency The serial communication reference is transferred to the frequency converter as a 16-bit word. The value is transferred in whole numbers 0 - ±32767 (±200%). 16384 (4000 Hex) corresponds to 100%. The value of the frequency converter’s present output frequency is transferred as a 16-bit word. The value is transferred as whole numbers 0 - ±32767 (±200%). 16384 (4000 Hex) corresponds to 100%.
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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU Bit 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 Bit = 0 Bit =1 Preset ref. lsb Preset ref.
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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU NB!: If the time-out period set in parameter 556 Bus time interval function is exceeded, relays 1 and 2 will lose their voltage if they have been activated via serial communication. Bits 13/14, Choice of Setup: Bits 13 and 14 are used to choose among the four menu Setups in accordance with the following table: Setup 1 2 3 4 Bit 14 0 0 1 1 Bit 13 0 1 0 1 This function is only possible if Multi-setups has been selected in parameter 004.
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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU speed reference. This may be the case, i.e. when the speed is ramped up/down at start/stop. Bit 08 = "1" means that the present motor speed equals the preset speed reference. The serial communication reference is transmitted to the frequency converter in the form of a 16-bit word. The value is transmitted as whole numbers 0 - ±32767 (±200 %). 16384 (4000 Hex) corresponds to 100 %.
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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU ■ Present output frequency Parameter Handling The value of the present output frequency of the frequency converter at any given time is transmitted as a 16-bit word. The value is transmitted in the form of whole numbers 0 - ±32767 (±200 %). 16384 (4000 Hex) corresponds to 100 %. The output frequency has the following format: 0-16384 (4000 Hex) 0-100 % (Par. 201 Output frequency low limit - Par. 202 Output frequency high limit).
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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU ■ Supported Modbus RTU Function Codes This section describes the following functions supported by the Modbus RTU. Read Coil Status (01HEX) Force Single Coil (05HEX) Force Multiple Coils (0FHEX) ■ Read Coil Status (01HEX) Description Reads the ON/OFF status of discrete outputs (0X references, coils) in the slave. Broadcast is never supported for reads. Query The query message specifies the starting coil and quantity of coils to be read.
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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU See example 1 Start Motor, Run Speed 40 %. Field Name Slave Address Function Coil Address HI Coil Address LO Quantity of Coils HI Quantity of Coils LO Byt Count Force Data HI (Coils 8-1) Force Data LO (Coils 10-9) Error Check (CRC) Example (HEX) 01 0F 00 00 00 0A 02 FF 03 - Response The normal response returns the slave address, function code, starting address, and quantity of coils forced.
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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU Field Name Slave Address Function Register Address HI Register Address LO Preset Data HI Preset Data LO Error Check (CRC) Example (HEX) 01 06 00 01 00 03 - Field Name Slave Address Function Starting Address HI Starting Address LO No. of Registers HI No of Registers LO Error Check (CRC) Example (HEX) 01 10 04 19 00 02 - Response The normal response is an echo of the query, returned after the register contents have been passed.
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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU ■ Exception Codes ■ Exception Code Tables When the frequency converter responds to the master via the Modbus serial network, it uses the function code field to indicate either a normal (error-free) response or an error (called an exception response). In an error-free response, the frequency converter simply echoes the original function code.
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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU ■ Appendix A - Examples The following examples illustrate different Modbus RTU commands. In case of malfunction please refer to the section Exception Codes. ■ EXAMPLE 1: Start Motor, Run Speed 40% Modbus function 0FHEX (Force Multiple Coils).
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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU Modbus message string: [01] [0F] [00] [00] [3C]+[04]: [00] [20] [04] [3C] [04] [00] [00] [89] [19] Stop Command: 000001000111100 = 043CHEX(reversed) (See Control Word Bit Descriptions) Speed Command: 0% Message returned to Modbus master from Modbus RTU Byte 0 Byte 1 Byte 2 Byte 3 Slave Function Coil Addr HI Coil Addr LO Address 01 0F 00 Byte 4 No. of Coils HI Byte 5 No.
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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU ■ EXAMPLE 4: Write Parameter 104 Motor Frequency, with 60 Hz (Data Type 6: UINT16) (Conversion factor = 0) Modbus Function 06HEX Preset Single Register Message sent to Modbus RTU from Modbus master Byte 0 Byte 1 Byte 2 Byte 3 Slave Function Register Addr Register Addr Address 01 HI 06 Modbus message string: [01] [06] [04]+[0F]: [01] [00+[3C]: 0F [0F] [00] 00 [3C] Byte 6+7 Error Check 3C -- [error check] Parameter 104 = 040FHEX Note that t
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VLT® 2800, VLT® 6000 HVAC and VLT® 8000 AQUA Modbus RTU Message sent to Modbus master from Modbus RTU Byte 0 Byte 1 Byte 2 Byte 3 Slave Function Byte Count Data HI (Reg Byte 4 Data LO (Reg Byte 5 Preset Data Byte 6 Data LO (Reg Address 01 45141) 00 LO 45141) 2C Byte 3-byte 6: 03 45140) 00 04 01 Byte 7+8 Error Check -- Value 0000012CHEX= 300 = 3 Amps All values are in hexadecimal. ■ EXAMPLE 6: Read Parameter 609 [8] "Log: Reference" This example shows how to read an index parameter.