WAGO PFC as a MODBUS MASTER Application note

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WAGO PFC as a

MODBUS MASTER

Application note

A201801, English

Version 1.0.0

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2 • General

WAGO Kontakttechnik GmbH Hansastraße 27 D-32423 Minden Phone: +49 (0) 571/8 87 – 0 Fax: +49 (0) 571/8 87 – 1 69 E-Mail: [email protected] Web: http://www.wago.com Technical Support Phone: +49 (0) 571/8 87 – 5 55 Fax: +49 (0) 571/8 87 – 85 55 E-Mail: [email protected]

Every conceivable measure has been taken to ensure the correctness and com-pleteness of this documentation. However, as errors can never be fully

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ex-Table of Contents • 3

1 Important

comments

To ensure fast installation and start-up of the units described in this manual, we strongly recommend that the following information and explanation is carefully read and adhered to.

1.1 Legal principles

1.1.1 Copyright

This manual is copyrighted, together with all figures and illustrations con-tained therein. Any use of this manual which infringes the copyright provisions stipulated herein, is not permitted. Reproduction, translation and electronic and photo-technical archiving and amendments require the written consent of WAGO Kontakttechnik GmbH. Non-observance will entail the right of claims for damages.

1.1.2 Personnel

qualification

The use of the product detailed in this manual is exclusively geared to spe-cialists having qualifications in PLC programming, electrical spespe-cialists or persons instructed by electrical specialists who are also familiar with the valid standards. WAGO Kontakttechnik GmbH declines all liability resulting from improper action and damage to WAGO products and third party products due to non-observance of the information contained in this manual.

1.1.3 Intended

use

For each individual application, the components supplied are to work with a dedicated hardware and software configuration. Modifications are only admit-ted within the framework of the possibilities documenadmit-ted in the manuals. All other changes to the hardware and/or software and the non-conforming use of the components entail the exclusion of liability on part of WAGO Kon-takttechnik GmbH.

Please direct any requirements pertaining to a modified and/or new hardware or software configuration directly to WAGO Kontakttechnik GmbH.

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Important comments • 5

1.2 Range of validity

This application note is based on the stated hardware and software of the spe-cific manufacturer as well as the correspondent documentation. This applica-tion note is therefore only valid for the described installaapplica-tion.

New hardware and software versions may need to be handled differently. Please note the detailed description in the specific manuals.

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6 • Description

2 Description

This document is to make the WAGO 750-8xx PFC a Modbus Master using the 750-650/000-018 (RS-232) or 750-653/000-018 (RS-485) module. Using the Modbus Master Function Block in a WAGO-I/O-PRO32 Program maks it possible create a Gateway between remote Modbus devices and a network such as Profibus, DeviceNet, Interbus, CanOpen and Ethernet networks. This type of gateway makes it possible to send and receive Modbus data across dif-ferent Networks. The following describes Configuring and networking the ex-ample node using the software and equipment listed below.

Modbus Master

750-833 Profibus PFC

750-650/000-018 RS-232, 9600,N,8,1, 5-Byte (Has to be a 5byte module) 750-600 End Module Slave Node 750-314 Modbus RS232,9600,N,8,1, RTU 750-402 4pt Input, 24VDC 750-402 4pt Input, 24VDC 750-504 4pt Output, 24VDC 750-504 4pt Output, 24VDC 750-600 End Module Profibus

The software and Scanner card used in this example is the SST Profibus card and software.

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Reference Material • 7

3 Reference

Material

3.1 PFC & Modbus Configuration

The PFC can act as a Modbus Master using the Modbus Master routine pro-gram. The routine program will need to be loaded with the following infor-mation:

Modbus Node Address – Address of the Node to read/write data Function Call – Function read/write Registers or bits

Register Address – Register Address to read/write data

Number of Addresses – How many Registers to read/write data Sende_Start – Use F_Trig function block to trigger Program

The following WAGO Modules used for the example:

Modbus Master 750-833 Profibus PFC

750-650/000-018 RS-232, 9600,N,8,1, 5-Byte (Has to be a 5byte module) 750-600 End Module Slave Node 750-314 Modbus RS232,9600,N,8,1, RTU 750-402 4pt Input, 24VDC 750-402 4pt Input, 24VDC 750-504 4pt Output, 24VDC 750-504 4pt Output, 24VDC 750-600 End Module Note:

Please check WAGO Part number to be sure that a 750-65x/000-018 5-Byte Tx/Rx module is ordered. The Modbus Master routine Program only works with this. The 3 byte Tx/RX modules will not work.

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8 • Reference Material

Modbus Master PFC to Modbus Slave Master Slave

TX --- 3 RX--- 2 Sig Com ---- 5 RTS Jumper to CTS

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Rung 1:

Does not need any changes by the programmer. It is the data cop to move data in and out of the program.

Rung 2:

This is the function block that does all the work to set up the Modbus data and do the Read/Write of the data.

The following explains the variables:

InterfaceData.SlaveAdress – Modbus Node address to read/write data. InterfaceData.FunctionCode – Function Code to perform data read/writes.

0x02 = Read Input Status

0x03 = Read Input Register (16 bits) 0x10 = Write Multiple Registers 0x05 = Force Single Coil

InterfaceData.StartAdress – Address of Bit/Register to perform function InterfaceData.NumberOfPoints – Number of bits/Registers to read/write Sende_Start – Use F_Trig to toggle function block to read/write data to

750-650/000-018 module

This example used a Profibus buscoupler to receive data from a Profibus net-work, Load the data into the correct variables and then cycle the data through a Modbus buscoupler.

Rung 3:

NODEADDRS – gets Modbus Node address and moves it to

InterfaceDa-ta.SlaveAdress.

Nodeaddrs gets data from %IB513 Network Variable area of the PFC which

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Rung 4:

Func_Code – gets the Modbus Function Code data and moves it to

Interface-Data.FunctionCode

InterfaceData.FunctionCode gets data from %IB512 Network Variable area of the PFC which was downloaded from the Profibus Network.

Rung 5:

IO_Addrs – gets the Modbus IO_Addrs data and moves it to

InterfaceDa-ta.StartAdress

IO_Addrs gets data from %IW257 Network Variable area of the PFC from the Profibus Network.

Rung 6:

Number_Points – gets the Modbus Number_Points data and moves it to

Inter-faceData.NumberOfPoints

Number_Points gets data from %IB517 Network Variable area of the PFC from the Profibus Network.

Rung 7:

ReceiveData.Buffer[3] – is the buffer where the return input data is located

and moves the data to PLCOUT256.

ReceiveData.Buffer[3] holds the input data from the Modbus read inputs function performed and moves it to PLCOUT256. PLCOUT256 is PFC address %QW256 to send the input data back to the Profibus Master.

Rung 8:

Input1 is clocked by the timer in Rung 9. When there is a rise and fall from the time in rung 9 the F_Trig function block sends a one-shot pulse to Sen-de_start.

Sende_Start – starts the function block with the Modbus data. When the

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3.2 Profibus Configuration

The software and Scanner card used in this example is the SST Profibus card and software.

The 750-833 GSD file can be downloaded from www.wago.com. The following GSD configuration was used for this example

0 750-833 PFC Profibus

1 PLC 750-650 is a place holder for the 750-650/000-001 RS-232 Module. The PLC 750-650 parameter was selected because the PFC Program will have control of the module.

2 Out4bytes is the number of bytes allocated to send data to Network Varia-ble Input area form the master to the PFC.

3 In4bytes is the number of bytes allocated to receive data from the Network Variable output area from the PFC to the master.

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In the configuration there are 5 choices:

· 750-XXX Allocates data for the network to control

· *750-XXX Allocates a place holder for the next module of the same type · PLC 750-xxx Allocates the module to be controlled by the PFC Program · OutxBytes – Number of bytes to be allocated to Network Variable inputs

Data from Master to PFC

· InxBytes – Number of Bytes to be allocated to Network Variable Outputs Data from PFC to Master

PFC Memory Map

The memory map of the PFC is as follows, This map applies to all PFC’s

Address 0-255 – Real world inputs and output module addresses

Address 256 – 511 – Network Variable area of memeory for the network to

read/write data to these registers.

The network can be configured to read/write data to the Network Variable area in the PFC. The PFC program will use the registers in the program to move data to and from the Network Variable area. Data should be moved in and out of the Network Variable area and let the PFC use the data to do the logic scan-ning to control the real world I/O. The PFC can also be configured so the in-puts or outin-puts are controlled by the Network.

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3.3 Mapping the inside of the PFC

In this configuration all the Profibus data has been mapped to the Network Va-riable area of the PFC.

Data From Master to PFC

Data From PFC to Master

PLCOUT256| Word 256 [Input Module data to Master] PLCOUT257| Word 257 [Input Module data to Master] PLCOUT258| Word 258 [Input Module data to Master] PLCOUT259| Word 259 [Input Module data to Master] Examples:

Reading Input status:

Function Code = 0x02

Start address = 0000 or 0001 or 0002 or 0003 Number of points = 1 (1 Input)

ReceiveData.Buffer.Buffer[3] = Value of 1st input (00 or 01)

Reading Holding registers:

Function Code = 0x03 Start address = 0000

Number of points = 1 (number of words registers to read) ReceiveData.Buffer.Buffer[4]= Value of the register being read

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Force Single Coil:

Function Code = 0x05

Start Address = 0000 or 0001 or 0002 or 0003 Number of points = 1 (One output)

InterfaceData.Data[1] = 0xFF to turn ON / 0x00 to turn OFF Or use ForceData;Buffer[0] to turn On/OFF

Write Multiple Registers:

Function Code = 0x10 Start Address = 0000

Number of Points = 1 (depends of number of register to write) InterfaceData.Data[1] = Value to write to PFC Register

It may be faster to use function 0x03 to read 16 bits at one time and function 0x10 to write 16 bits at one time

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Slave Setup:

The Modbus slave was set up for the following 9600,N,8,1, RTU, No Watch Dog

The dip switches were set as follows F switch =1 Dn 2 Up 3 Up 4 Dn 5 Dn 6 Dn P switch =1 Dn 2 Dn 3 Dn 4 Up 5 Up 6 Up 7 Up 8 Dn

Addition to the PFC Program:

An addition to this program would be to get the data from the Master and send it to the Slave for a register data write.

Add the following run to the program.

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Germantown, Wi 53022 Phone: 1-262-255-6333 Fax: 1-262-255-3232