2gcs214012a0050 - rs485 user guide

7/28/2019 2GCS214012A0050 - RS485 User guide

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User guide RVT Modbus RS485 adapter


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Table of contents1 INTRODUCTION .............................................................................................................................................................................................................................................................................. 3

2 OVERVIEW ........................................................................................................................................................................................................................................................................................ 3

2.1 INTRODUCTION TO MODBUS ...................................................................................................................................................................................................................................... 3

2.2 MODBUS ADAPTER MOUNTING ................................................................................................................................................................................................................................. 3

2.3 MODBUS ADAPTER WIRING ......................................................................................................................................................................................................................................... 4

2.4 MODBUS ADAPTER TERMINAL SWITCH ............................................................................................................................................................................................................... 5

2.5 RVT ACCESS LEVEL ........................................................................................................................................................................................................................................................... 5

2.6 RVT PARAMETER SETTINGS FOR MODBUS COMMUNICATION ........................................................................................................................................................... 6

2.7 MODBUS DATA TABLE ....................................................................................................................................................................................................................................................... 7

3 APPENDIX : REFERENCES .................................................................................................................................................................................................................................................... 7

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1 INTRODUCTIONThis guide is designed to help you quickly install the RVT Modbus adapter and to give an overview of the commissioning process. This guide makesreference to more detailed documents made for installators, commissioning people and network managers who are familiar with Modbus protocol andrelated matters.

2 OVERVIEW2.1 Introduction to ModbusModbus is a serial, asynchronous protocol. The Modbus protocol does not specify the physical interface. The RVT Modbus adapter has an RS-485interface.[Detailed information is available in RVT Modbus RS485 adapter Installation and Start up Guide ]Modbus is designed to allow a communication between components of an installation including one or several supervision systems. Amongst the countless advantages and benefits of a communication capability, Modbus is a well spread protocol in the industrial world and allow, for example, interconnection between components for linked actions and information centralisation.Gateway between Modbus and other fieldbus can be found in the market giving access to several other fieldbus systems.The Modbus adapter is an optional device for ABB Power IT Power Factor Controller RVT which enables the connection of the RVT to a Modbus sys-tem. The RVT is considered as a slave unit in the Modbus network.With the RVT Modbus adapter, all RVT information (measurements, serial number, alarm messages,..) and all parameters settings (switching strat-egy, protection levels,..) are accessible.[Detailed information is available in RVT Installation and Operating Instructions ]

2.2 Modbus adapter mounting

The Modbus adapter has a customiseddesign to fit the RVT case.

1) plug the RVT Modbus adapter in the RVTdedicated connectors.

2) Fix the RVT Modbus adapter with the fix-ing screw (included in the delivery).

3) Ensure that all connections are tight

RVT RS485 Modbus adapter

To be connected to RVTRS232 input (optical trans-ceiver) To be connected to the RVT

power supply connector

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2.3 Modbus adapter wiring

Please note that if the RVT is already installed and con-nected, the RVT power supply has to be switched OFFduring the Modbus adapter connection.[Detailed information on RVT mounting is available in RVT Installation and Operating Instructions ]

Screw terminals :GND : ground A : RS485 non inverting wireB : RS485 inverting wire

cable

Cable connection between RVT RS485 Modbus adapter andModbus Master

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A proper cable must be used for the connection between the RVT Modbus adapter and the Modbus master. For a RS-485 connection and up to 1200m(4000 ft), a 24 AWG twisted pair with foil shield and drain wire on each pair is usually required (Belden 9841 for 2-wire and 9729 for 4-wire or equiv.)[Detailed information is available in RVT Modbus RS485 adapter Installation and Start up Guide ]Please note that if the RVT is already installed and connected, the RVT power supply has to be switched OFF during the Modbus adapter connection.[Detailed information on RVT wiring is available in RVT Installation and Operating Instructions ]

2.4 Modbus adapter terminal switch

Depending on the position of the RVT-Modbus in the Modbus line topology, the resistor termination switch must be switched ON or OFF.

If the RS485 Modbus adapter is one of the two ending station on the communication line, the resistor termination switch must be switched in theON position. If not, it must be switched in the OFF position.

Make sure all other Modbus stations (master and slaves) are properly connected.[Detailed information is available in RVT Modbus RS485 adapter Installation and Start up Guide ]

2.5 RVT access level

The RVT has several access level in order to prevent unauthorised modification of all or some of the parameters. Three levels are described herebelow. The access levels have to be taken into account for parameter settings through Modbus as same rules apply.

Locking switch:

A locking switch, located at the back of the RVT allows the RVT to be locked in AUTO mode or in MAN mode.When the lock is set:- a will appear in the upper left-hand corner of the graphics display.- a will appear beside the Change mode and Commissioning menus and beside all the settings.- access to the Change mode and Commissioning menus will be denied.- no modification can be made to the settings (including the Event logging settings).- the setting values may be consulted.

Resistor termination switch

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This access level can not be modified by software (with RVT padlock or Modbus communication). Pressing the locking switch physically can onlymodify the access permission.

AUTO/MAN mode:The RVT has three functional modes: AUTO, MAN and SET modes.When the AUTO or the MAN mode is set:

- a will appear beside all the settings.

- access to the Commissioning menu will be denied.- access to the Change mode menu will be allowed.- the setting values may be consulted.- no modification can be made to the settings (except to the Event logging settings).In SET mode, the RVT parameters can be set manually and automatic and guided commissioning can be performed.Please note that parameter settings can only be modified in SET mode.

Bank settings item:The bank settings item, available at the bottom of the bank settings list, can be either locked or unlocked.When the bank settings item is set as locked (whatever the Mode used):

- a will appear beside all the bank settings.- no modification can be made to the bank settings- the bank settings values may be consulted.- the installation and user settings can be modified, if the locking switch is unlocked.Once locked, the bank set item can be unlocked by entering the following key sequence (in SET mode):

2.6 RVT parameter settings for Modbus communication

Modbus protocol

By selecting and validating the Modbus protocol item, the RVT is able to communicate in a Modbus supervision system. All RVT parameters as well as all the RVT measurements are accessible.Baud rate: to adjust the communication speed (bits/second).

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Parity: to set the parity checking.Stop bit: to set the number of stop bit(s).Slave address: to adjust the address of the Modbus/RTU slave.The Modbus master will refer to this address for each query / answer transaction with this RVT.Modbus lock: the Modbus lock item allows to lock the parameters access through the RVT padlock. Parameters can be only modified through theModbus communication.

2.7 Modbus data tableEach data, measurement value and parameter setting available on the RVT can be read or set (parameter settings) through the Modbus communi-cation.The Modbus data table gives all the necessary information (addresses, access levels and storage types) for a proper Modbus communication.[Detailed information is available in RVT Modbus RS485 adapter RVT Modbus datatable ]

3 Appendix : references

Installation and Operating Instructions Power IT Power Factor Controller RVTProgrammers Manual RVT Modbus Data TableInstallation and start-up guide RS485 Modbus Adapter

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This product has been certified by ABB Group as Industrial IT Enabled TM. All productinformation is supplied in interactive electronic format, based on ABB Aspect Object TMtechnology.Plug and Produce TM installation and integration with other Industrial IT certified productsis available through the ABB Aspect Integrator TM Platform.

While all care has been taken to ensure that the information contained in this publi-cation is correct, no responsibility can be accepted for any inaccuracy. We reserve theright to alter or modify the information contained herein at any time in the light of tech-nical or other developments. Technical specifications are valid under normal operat-ing conditions only. We do not accept any responsibility for any misuse of the productand cannot be held liable for indirect or consequential damages. 2

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ABB n.v.Power Quality Products Avenue Centrale, 10Zoning Industriel de JumetB-6040 Charleroi (Jumet), BelgiumPhone : +32 71 250 811Fax : +32 71 344 007

2gcs214012a0050 - rs485 user guide

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