Schneider Electric Altivar31 User Manual

Altivar 31

####

Modbus

User’s manual

11/2009

1624597

www.schneider-electric.com

While every precaution has been taken in the preparation of this document, Schneider Electric SA assumes no liability for any omissions or errors it may contain, nor for any damages resulting from the application or use of the information herein.

The products described in this document may be changed or modified at any time, either in appearance or in their operation. Their description can in no way be considered contractual.

Presentation ________________________________________________________________________________________________ 3 Connection to RS485 bus ______________________________________________________________________________________ 4 Modbus protocol _____________________________________________________________________________________________ 8 Appendix: Non-standard RS485 schematics_______________________________________________________________________ 13

2 1624597 11/2009

Presentation

The Modbus socket on the Altivar 31 can be used for the following functions:

• Configuration

• Settings

• Control

• Monitoring

The ATV31 drive supports:

• The 2-wire RS485 physical layer

• The RTU transmission mode

This guide contains information on installation and describes the Modbus services available. The "communication variables" guide describes the operating modes, as well as the Altivar 31 variables and parameters which can be accessed via the communication bus.

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Connection to RS485 bus

8........................1

Connection to ATV31

Connection accessories should be ordered separately (please consult our catalogues).

Connect the RJ45 cable connector to the ATV31 connector.

Pin out of the ATV31 RJ45 Connector

View from underneath

Pin Signal

1CAN_H

2CAN_L

3CAN_GND

4D1 (1)

5D0 (1)

6 Not connected

7VP (2)

8 Common (1)

(1) Modbus signals (2) Supply for RS232 / RS485 converter or a remote terminal

Protection against interference

• Use the Schneider-Electric cable with 2 pairs of shielded twisted conductors (reference: TSXCSA100, TSXCSA200, TSXCSA500).

• Keep the Modbus cable from the power cables (30 cm minimum).

• Make any crossovers of the Modbus cable and the power cables at right-angles, if necessary.

• Connect the cable shielding to the ground of each device.

For more information, please refer to the TSX DG KBL E guide: "Electromagnetic compatibility of industrial networks and fieldbuses".

RS485 bus schematic

The RS485 standard allows variants of different characteristics:

• polarisation

• line terminator

• distribution of a reference potential

• number of slaves

• length of bus

The new Modbus specification published on the Modbus.org site in 2002 contains precise details of all these characteristics. They are also summarised in the next paragraph (Standard schematic). The new Schneider-Electric devices conform to this specification.

Some devices comply with earlier specifications. The two most widespread are described in the appendices:

• "Uni-Telway schematic" page 13

• "Jbus schematic" page 14

Requirements enabling different types of protocol to coexist are given in the appendix:

• "Mixed schematic" page 15

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Connection to RS485 bus

1n F

650 Ω

120 Ω

1n F

120 Ω

5 V

0 V

Common

Master

Standard schematic

The standard schematic corresponds to the Modbus specification published on the Modbus.org site in 2002 (Modbus_over_serial_line_V1.pdf, Nov 2002) and in particular to the schematic of the 2-wire multidrop serial bus.

The ATV31 drive conforms to this specification.

Schematic diagram:

Slave 1

Type of trunk cable

Maximum length of bus

Maximum number of stations (without repeater)

Maximum length of tap links

Bus polarisation

Line terminator

Common polarity

Slave n

Shielded cable with 1 twisted pair and at least a 3rd conductor 1000 m at 19200 bps with the Schneider-Electric TSX CSAppp cable

32 stations, ie. 31 slaves

• 20 m for one tap link

• 40 m divided by the number of tap links on a multiple junction box

• One 450 to 650 Ω pulldown resistor at 5 V (650 Ω recommended)

• One 450 to 650

Ω pulldown resistor at the Common (650 Ω recommended)

This polarisation is recommended for the master.

One 120 Ω 0.25 W resistor in series with a 1nF 10 V capacitor

Yes (Common), connected to the protective ground at one or more points on the bus

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Connection to RS485 bus

43 46 6 5

A TV 31

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Connection via RJ45 wiring system

1 Master (PLC, PC or communication module)

2 Modbus cable depending on the type of master (see table)

3 Modbus splitter block LU9 GC3

4 Modbus drop cables VW3 A8 306 Rpp

5 Line terminators VW3 A8 306 RC

6 Modbus T-junction boxes VW3A8306TFpp (with cable)

7 Modbus cable (to another splitter block) TSX CSAp00

Connection accessories

Description Reference

Modbus splitter block 10 RJ45 connectors and 1 screw terminal LU9 GC3

Modbus T-junction boxes With integrated cable (0.3 m) VW3 A8 306 TF03

With integrated cable (1 m) VW3 A8 306 TF10

Line terminators

For RJ45 connector R = 120 Ω, C = 1 nF VW3 A8 306 RC

R = 150 Ω (specific to "Jbus schematic" page 14) VW3 A8 306 R

Connecting cables

Description Length

Cables for Modbus bus

RS 485 double shielded twisted pair cables

Type of master Master interface Modbus connection accessories for RJ45 wiring system

Twido PLC

TSX Micro PLC Mini-DIN RS485 connector

TSX Premium PLC TSX SCY 11601 or

Ethernet bridge (174 CEV 300 10)

Profibus DP gateway (LA9P307)

Fipio (LUFP1) or Profibus DP (LUFP7) or DeviceNet (LUFP9) gateway

Serial port PC Male SUB-D 9 RS232 serial

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3 1 RJ45 connector and 1 stripped end VW3 A8 306 D30

0.3 2 RJ45 connectors VW3 A8 306 R03

1 2 RJ45 connectors VW3 A8 306 R10

3 2 RJ45 connectors VW3 A8 306 R30

100 Supplied without connector TSX CSA 100

200 Supplied without connector TSX CSA 200

500 Supplied without connector TSX CSA 500

Adaptor or mini-DIN RS485 interface module

Adaptor or screw terminal RS485 interface module

port

PCMCIA card (TSX SCP114)

TSX SCY 21601 module (SUB-D 25 socket)

PCMCIA card (TSX SCP114)

Screw terminal RS485 3 m cable fitted with an RJ45 connector and stripped at the

RJ45 RS485 1 m cable fitted with 2 RJ45 connectors VW3 P07 306 R10

RJ45 RS485 0.3 m cable fitted with 2 RJ45 connectors or

port PC

Connectors Reference

Description Reference

3 m cable fitted with a mini-DIN connector and an RJ45 connector

3 m cable fitted with an RJ45 connector and stripped at the other end

3 m cable fitted with a mini-DIN connector and an RJ45 connector

Stripped cable TSX SCP CM 4030

Cable fitted with a SUB-D 25 connector and stripped at the other end (for connection to the screw terminals of the LU9GC3 splitter block)

Stripped cable TSX SCP CM 4030

other end

1 m cable fitted with 2 RJ45 connectors or 3 m cable fitted with 2 RJ45 connectors

RS232/RS485 converter and 3 m cable fitted with an RJ45 connector and stripped at the other end (for connection to the screw terminals of the LU9GC3 splitter block)

TWD XCA RJ030

VW3 A8 306 D30

TWD XCA RJ030

TSX SCY CM 6030

VW3 A8 306 D30

VW3 A8 306 R03 or VW3 A8 306 R10 or VW3 A8 306 R30

TSX SCA 72 and VW3 A8 306 D30

+ 11 hidden pages

Schneider Electric Altivar31 User Manual

Contents

Presentation

Connection to RS485 bus

Connection to ATV31

Protection against interference

RS485 bus schematic