Communication AC500 Modbus TCP

Scalable PLC AC500

© ABB Group – Version 3.1 (2012-07) Technical Guides

© ABB Group March 11, 2013 | Slide 2

Modbus TCP with AC500

Configuration and parameterization

Program in CoDeSys

Modbus TCP Communication Coming up

© ABB Group March 11, 2013 | Slide 3

AC500 is server. It is exchanging

data on client’s request.

CP600 is client. It is initiating the

communication.

Modbus TCP Communication AC500 as Server and / or Client

Data exchange between CPUs.

Modbus TCP communication also

via CM577 possible.

Each PLC can act as client and /or

server.

© ABB Group March 11, 2013 | Slide 4

Modbus TCP with AC500

Configuration and parameterization

Program in CoDeSys

Modbus TCP Communication Coming up

© ABB Group March 11, 2013 | Slide 5

Modbus TCP Communication Configure Modbus TCP (1)

Add Modbus TCP on Onboard_Ethernet or CM577_ETH

Result:

© ABB Group March 11, 2013 | Slide 6

Modbus TCP Communication Configure Modbus TCP (2)

If the Port is acting as a server

configure number of

connections to be created

simmultaneously to different

clients

Byte order for AC500

communication is Big endian =

Motorola byte order

The other parameters could be

changed due to optimize the

communication.

© ABB Group March 11, 2013 | Slide 7

Modbus TCP Communication Configure Modbus TCP (3)

In the server project the

Modbus buffer area could be

selected as %M or %R area

(default: %M area)

Optionally in the server project

areas could be protected

against write and / or read

access by clients.

Writing / reading is disabled

beginning at the set address

and is valid up to the set end

address (inclusive).

© ABB Group March 11, 2013 | Slide 8

Modbus TCP with AC500

Configuration and parameterization

Program in CoDeSys

Modbus TCP Communication Coming up

© ABB Group March 11, 2013 | Slide 9

Modbus TCP Communication Client: Program in CoDeSys

Enabling parameter (0 -> 1 edge)

Number of Communication Module

Function code. Here Read registers (words)

Addr. of the slave connected serial to the server

10 words

Starting from Server address 0 (%MW0.0 or %RW0.0)

Copy to own memory area starting with address

of the operand (an array or an addresable area)

IP-address of the Server

Result of

data

exchange

This FB is only for the Client (no FB for Server).

© ABB Group March 11, 2013 | Slide 10

Modbus TCP Communication Function Codes

01 or 02 read n coils (bits) 255 bits (up to firmware version V01.33)

1800 bits (from firmware version V01.41)

03 or 04 read n registers (words) 100 words / 50 double words

05 write one coil (bit) 1 bit

06 write one register (word) 1 word

07 read 8 coils (bits) 8 bits

15 write n coils (bits) 255 bits (up to firmware version V01.33)

1800 bits (from firmware version V01.41)

16 write n registers (words) 100 words / 50 double words

22 mask one register (word) only with CPUs with Onboard Ethernet

23 read and write n registers

(word)

only with CPUs with Onboard Ethernet

AC500 supports following Modbus function codes:

© ABB Group March 11, 2013 | Slide 11

Modbus TCP Communication Program in CoDeSys

Enable FB by a puls signal

FB is dedicated to the CPU internal ETH port

IP-addres of the server is 10.33.71.175, no routing to another serial slave

Write 5 words to the 11. word of the server’s Modbus buffer (%MW0.10 or

%RW0.10) from own area beginning with the address of the variable

ARRAYofWORD

© ABB Group March 11, 2013 | Slide 12

Modbus TCP Communication Program in CoDeSys

Enable FB by a puls signal

FB is dedicated to the CPU internal ETH port

IP-addres of the server is 10.33.71.174, no routing to another serial slave

Read 5 words to the 11. word of the server’s Modbus buffer (%MW0.10 or

%RW0.10) from own area beginning with the address of the variable

ARRAYofWORD

© ABB Group March 11, 2013 | Slide 13

Modbus TCP Communication Read / Write Addresses

Input and Output cannot be directly accessed by using Modbus

The address assignment for word and double word accesses is done according to the

following table :

Line 0 %MW0.0 to %MW0.32767 and line 1 %MW1.0 to %MW1.32767

Line 0 only for PM554_ETH, PM564_ETH and PM57x_ETH

© ABB Group March 11, 2013 | Slide 14

Cross-References to Documentation

1. CoDeSys Help\Target System\

AC500 / S500\ Function Block Libraries AC500 \

Ethernet Library

2. CoDeSys Help\Target System\

AC500 / S500\System Technology \System

Technology of the AC500 Communication

Modules\The Ethernet Communication Module\

Modbus on TCP/IP

© ABB Group March 11, 2013 | Slide 15