Modbus on Ethernet

applicomIO® 2.2

Modbus on Ethernet

applicom international

Copyright © 1989-2002 applicom international.

Table of contents

1. Description of Modbus on Ethernet 1 General.................................................................................................................................1 applicomIO® functionalities ...............................................................................................2

2. Using the Modbus on Ethernet equipment library 3 Management of the equipment library.................................................................................3

3. Using Modbus on Ethernet network detection 4 Automatic detection of equipment present ..........................................................................4

4. Properties of the Modbus on Ethernet master 7 Configuration of the Modbus on Ethernet master................................................................7 Ethernet configuration .........................................................................................................7 TCP/IP protocol configuration...........................................................................................11

5. Modbus on Ethernet device properties 13 General configuration ........................................................................................................13 Messaging parameters .......................................................................................................15 Configuration of inputs......................................................................................................17 Configuration of outputs....................................................................................................20

6. Step by step implementation 23 Adding the PCI-ETHIO applicomIO® board .....................................................................23 Equipment library ..............................................................................................................27 Choice of configuration method ........................................................................................27

Automatic configuration......................................................................................28 Manual Configuration .........................................................................................30 Properties of the device to be inserted in the configuration.................................31 Properties of the master in the configuration.......................................................31

Downloading the configuration .........................................................................................32

7. Tests and diagnostics 33 On line actions ...................................................................................................................33 The diagnostic tool ............................................................................................................33 Diagnostic of the Modbus on Ethernet channel .................................................................34

Diagnostic of the TCP/IP layer............................................................................35 Diagnostic of server devices................................................................................38

8. Status 43 General...............................................................................................................................43 applicomIO status ..............................................................................................................44

applicomIO® 2.2 Modbus Ethernet Table of contents • i

ii • Table of contents applicomIO® 2.2 Modbus Ethernet

1. Description of Modbus on Ethernet

General

The Modbus on Ethernet protocol is used to connect Modbus remote input/output devices on an Ethernet TCP/IP network.

The Modbus on Ethernet protocol uses the TCP or UDP layers to carry Modbus messaging based on the Modicon "Open Modbus/TCP Specifications" which can be obtained from the site: http://www.modbus.org.

See also: - in the knowledge base:

1 : TCP/IP appendix

applicomIO® 2.2 Modbus Ethernet Description of Modbus on Ethernet • 1

applicomIO® functionalities

The Modbus on Ethernet master includes the following features :

Speeds supported:

Auto/10/100 Mbits

Connector type:

RJ45

Protocols supported:

TCP

UDP

Devices supported:

max. 127 devices

Equipment type: "Generic Modbus"

Modbus Scanner:

Polling of inputs in "cyclic" mode per period multiple of 10 ms

Polling of outputs in "cyclic" or "cyclic and on value change" mode per period multiple of 10 ms

Total size of inputs/outputs: 14 kilobytes at the most

applicomIO® console

Automatic detection of devices present on the network

Diagnostic of the applicomIO® configuration

On line access to devices not configured

2 • Description of Modbus on Ethernet applicomIO® 2.2 Modbus Ethernet

2. Using the Modbus on Ethernet equipment library

Management of the equipment library

Management of the equipment library is carried out in the "Equipment library" area.

The equipment library can be used to insert manually 1 a new "Generic Modbus" device in the configuration.

Voir également : - in this manual:

1 : Manual Configuration

applicomIO® 2.2 Modbus Ethernet Using the Modbus on Ethernet equipment library • 3

3. Using Modbus on Ethernet network detection

Automatic detection of equipment present

Detection of equipment on the Modbus on Ethernet network is carried out in the "Network detection" 2 area.

To carry out detection the applicomIO® interface must be initialized 3.

• If this is necessary, the applicomIO® console asks you if you want to reinitialize the interface with a minimum configuration:

o no devices

o configuration 1 of TCP/IP protocol of the Modbus on Ethernet master (parameter in the general tab of the TCP/IP node)

• Otherwise, configuration will be carried out automatically with the minimum configuration

You can then define an IP address range to be detected by entering start and end addresses.

4 • Using Modbus on Ethernet network detection applicomIO® 2.2 Modbus Ethernet

If you choose "OK", network detection starts with the new address range.

If you choose "Cancel", network detection is abandoned.

If you choose a very large range of addresses (more than 1024 addresses), the applicomIO® console will prompt you to confirm your choice since polling a large address range takes a considerable amount of time.

During network detection, you can stop the detection of devices at any time by pressing "cancel"

applicomIO® 2.2 Modbus Ethernet Using Modbus on Ethernet network detection • 5

When detection is finished, all devices present on the network are displayed in the "Network detection" tab

Modbus device: It will be represented in the detection tree by: . You can therefore find the device type (Modbus) and its IP address. Only these devices can be added to the configuration.

Other device types: They are represented by: In this case only the IP address is specified. These devices were not recognized as Modbus devices, although connected to the network. You cannot add this type of device to the configuration.

See also: - in this manual:

TCP/IP protocol configuration

- in the documentation:

2 : Configuration : ‘Network detection’ tab

3 : Implementation : Initialization

6 • Using Modbus on Ethernet network detection applicomIO® 2.2 Modbus Ethernet

4. Properties of the Modbus on Ethernet master

Configuration of the Modbus on Ethernet master


Ethernet configuration


Ethernet configuration

applicomIO® 2.2 Modbus Ethernet Properties of the Modbus on Ethernet master • 7

"General" tab

Request time-out Maximum time separating the transmission of a request by the applicomIO® client from the server's response.

When the device takes longer than this time-out to reply, the current request returns status 55 "Message lost".

Value in seconds, from 2 to 255; 10 by default.

8 • Properties of the Modbus on Ethernet master applicomIO® 2.2 Modbus Ethernet

"Ethernet" tab

Transmission speed Used to select the transmission speed. "Auto 10/100MB" corresponds to automatic detection of the transmission speed.

Default speed: "auto 10/100MB"

Frame format Ethernet frame format used on the network. Only possible choice: Ethernet II frame format, since frame format 802.3 is not supported.

Connection lifetime Maximum inactivity time of a TCP connection. A connection is active when data is being carried or when it is maintained (procedure configurable in TCP). Past this time the connection is closed, to avoid having too many connections (max. 128) when the partner is absent.

Value in minutes, from 2 to 60; 3 by default.

Automatic address calculation If it is activated, the Ethernet address is automatically calculated using the applicom® IEEE address and the board serial number.

If this option is deactivated the Ethernet address must be entered manually in hexadecimal.

Ethernet address Address on 6 bytes uniquely defining the Ethernet channel on the network.

Manual entry ("Automatic address calculation" in "Manual entry"):


Enter the Ethernet address in hexadecimal. If you enter an address, then this is the one which will be used.

Automatic address calculation:

This address can be calculated automatically using the applicom® IEEE address and the board serial number (see Figure 1 below).

The serial number is indicated by labels on the applicomIO® interface (on the metal plate at the back and on the copper) or displayed during initialization of the interface ("pcinitIO").

Example:

Ethernet address of an applicomIO® interface with serial number 20100 i.e. 4E84 in Hexadecimal (see Figure 2 below).

applicom® IEEE address

Interface serial number (in hexadecimal)

00 AO 91 xx xx xx

Figure 1

00 AO 91 00 4E 84

Figure 2



"General" tab

IP address of the applicom channel Area of 4 bytes entered in decimal notation with decimal point representing the Internet address or IP address 1 of the applicomIO® board channel.

IP address of the gateway IP address of a machine which can perform routing 2 to another network (internal or external).

Subnetwork mask Used to define the addresses 3 to be routed by the gateway 2.

Value "0.0.0.0" to "255.255.255.255"; "255.255.255.0" by default.


"Advanced" tab

Number of retries Number of times that the applicomIO® board tries to resend a TCP packet that has not been acknowledged.

Value from 1 to 12; 2 by default.

Interval between two retries Maximum interval between two retries. The time between the retries increases on each retry. This parameter together with to the number of retries is therefore used to determine a global time-out 4 for transmission of a TCP packet.

Value in seconds from 1 to 5; 1 by default.

A TCP packet that has not been acknowledged and ending in time-out results in the connection being closed. The function then returns status 33 "Time-out".

Connection maintenance Activation of the TCP/IP function "keep alive", used to keep TCP connection open with a periodic check that the partner is present.


1 : TCP/IP appendix: IP address

2 : TCP/IP appendix: Gateway

3 : TCP/IP appendix: Subnetwork mask

4 : TCP/IP appendix: TCP Time-Out


5. Modbus on Ethernet device properties

General configuration

Device designation

Topic name Enables the OPC and DDE servers to access the variables of this device. For further details refer to the "DDE and OPC servers" manual.

Number Number of the applicomIO® device to be chosen in the list of devices not configured.

Value from 0 to 127.

applicomIO® 2.2 Modbus Ethernet Modbus on Ethernet device properties • 13

Link the parameters Checkbox to activate the link of the device number with the device IP address: the device number will then correspond to the station number of the IP address. Depending on the device type, this number could be linked to another parameter located in the messaging parameters.

Active configuration Checkbox to activate the configuration of the device in the applicomIO® interface: used to delete a device from the applicomIO® interface, whilst keeping its configuration in the console.

Comments Free text related to a device. The total number of characters must not exceed 80.

Network properties

IP address IP address of the partner device.

The complete address in TCP/IP includes an IP address and a port number (TCP Port), the port number being used to identify the application using the connection. Generally the port number is predefined by the PLC manufacturer.

Transport protocol Used to choose between TCP transport protocol and UDP transport protocol.

Destination port Port on the targeted equipment that the applicomIO® master must connect to. The values can range from 1 to 65535.

Remark concerning the source port: This source port contains the port number of the applicomIO® master which will be used by the target device for its response. When UDP transport protocol is selected, the source port is automatically set to 0.

Description Provides help on the selected field.

14 • Modbus on Ethernet device properties applicomIO® 2.2 Modbus Ethernet

Messaging parameters

Double / floating word format Defines word order for double and floating words in the device.

Word1 Address : 400001

Word2 Address : 400002

Format 0………….Double Word………..32 Intel Word1(400001) Word2(400002) Motorola Word2(400002) Word1(400001)

Format : Little Endian (Intel), Big Endian (Motorola).

Unit identifier On TCP/IP, the "Slave address" field of the Modbus protocol is replaced by a "Unit identifier" byte which can be used to communicate via bridge or gateway type devices using a single IP address and supporting several independent end devices.

This number is linked to the applicom® device number if the "Link the parameters" box is checked.

Value : from 1 to 255, 1 by default

Single bit writing support


In order to use a Modbus 5 function code to write 1 a single bit in a device. If this option is not chosen, Modbus 15 function code will be used.

Single word writing support In order to use a Modbus 6 function code to write 1 a single word in a device. If this option is not chosen, Modbus 16 function code will be used.


1 : Configuration of outputs


Configuration of inputs

This tab defines the exchange blocks used by the Modbus master to read the inputs of the device.

List of exchange blocks

Use buttons “Move Up” and “Move Down” to arrange the data of the exchange blocks 2.

Description of an exchange block

Syntax This syntax allows you to define the address and the exchange type: 0xxxxx for the internal bits, 1xxxxx for the input bits, 4xxxxx for the internal words, 3xxxxx for the input words (where xxxxx is the data address, e.g.:400004).

Syntax Exchange type Function code

MODBUS 000001 - 065536 Read bits 1 100001 - 165536 Read input bits 2 400001 - 465536 Read words 3 300001 - 365536 Read input words 4


Number Number of data items of the specified type to read.

Value for words : from 1 to 127, 1 by default.

Value for bits : from 1 to 2040, 1 by default.

Period Refresh period 3 for this exchange block 2. The value must be a multiple of 10 ms. The zero period (0) chained the refresh of the bloc.

Value: from 0 to 65530, 10 by default.

Root name Allows you to define a root of the item 1 name to create new OPC/DDE tags.

The items are created automatically with this root.

OPC/DDE type Defines the variable type corresponding to the default item 1 in OPC/DDE for this exchange block.

Remark: There are two ways to edit an exchange block:

Either directly in the list

Or by double clicking on an exchange block (or pressing the SPACE bar). A new box is then displayed, used to configure the exchange block parameters one by one. This solution provides more information on the configuration possibilities for each parameter, especially the min. max. and default values.


See also: - in the documentation:

1 : Configuration of topics and items: Principle for naming input/output variables

- in the knowledge base:

2 : Exchange block: Purpose of an Exchange block

3 : Exchange block: Configuring the period of an Exchange block 4 : Organization of Modbus on Ethernet device inputs / outputs

- in this manual:

5 : Messaging parameters


Configuration of outputs

This tab defines the exchange blocks used by the Modbus master to write the outputs of the device.

List of exchange blocks

Use buttons “Raise” and “Lower” to arrange the data of the exchange blocks 2.

Description of an exchange block

Syntax This syntax allows you to define the address and the exchange type: 0xxxxx for the internal bits, 4xxxxx for the internal words, (where xxxxx is the data address, e.g.:400004).

The Modbus function code 4 will depend on the used syntax.

Syntax Echange type MODBUS Function

Code Write N bits 15 000001 - 065536 Write 1 bit 5


Write N words 16 400001 - 465536 Write 1 word 6

Number Number of data items of the specified type to write.

Value for words : from 1 to 127, 1 by default.

Value for bits : from 1 to 2040, 1 by default.

Mode Defines the refresh mode of the exchange block.

The modes are: "Cyclic" or "Cyclic and on change of value".

In "Cyclic" mode, the outputs are refreshed at a fixed period for this exchange block.

In "Cyclic and on change of value" mode, refresh is carried out at a fixed period and also on change of status.

Period Refresh period 3 for this exchange block in cyclic mode. The value must be a multiple of 10 ms.

Value: from 10 to 65530, 500 by default

Root name Allows you to define a root of the item 1 name to create new OPC/DDE tags.

The items are created automatically with this root.

OPC/DDE type Defines the variable type corresponding to the default item 1 in OPC/DDE for this exchange block.

Remark: There are two ways to edit an exchange block:

Either directly in the list

Or by double clicking on an exchange block (or pressing the SPACE bar). A new box is then displayed, used to configure the exchange block parameters one by one. This solution provides more information on the configuration possibilities for each parameter, especially the min. max. and default values.



1 : Configuration of topics and items: Principle for naming input/output variables


2 : Exchange block: Purpose of an Exchange block

3 : Exchange block: Configuring the period of an Exchange block 4 : Organization of Modbus on Ethernet device inputs / outputs

- in this manual:

5 : Messaging parameters


6. Step by step implementation

Adding the PCI-ETHIO applicomIO® board

Add a new PCI-ETHIO applicomIO® board 1 with the menu command "Description / Add a board"

or with the button

If the board is installed in your machine:

The board was detected correctly, press OK.

Enter the IP addresses of the applicomIO® master, the gateway if any and the subnetwork mask.

applicomIO® 2.2 Modbus Ethernet Step by step implementation • 23

You must then reboot your machine so that this configuration is taken into account by the applicomIO® driver, then restart the applicomIO® console.

If the board is not installed in your machine:

24 • Step by step implementation applicomIO® 2.2 Modbus Ethernet

No board is detected, press "Diagnostic and manual configuration"


In "Diagnostic and manual configuration", select PCI-ETHIO, then press OK.


1 : Configuration: Adding and deleting a board


Equipment library

The library contains only one device. This is a generic device which can be used for any Modbus on Ethernet device that you want to add to your configuration.

Choice of configuration method

After correctly configuring the applicomIO® master (choosing it an IP address), two configuration 1,2 methods are available:

Automatic configuration Your applicomIO® board is already connected to the Ethernet and the IP addresses of your devices are correctly configured.

Manual Configuration Your applicomIO® board is not yet linked to the Ethernet, but you know the characteristics of the devices to be configured.


1 : Automatic configuration

2 : Manual Configuration


Automatic configuration

Choose the “Network detection” tab in the resources area.

Activate network scanning 1 with the menu command "Network/Read network configuration..." or

with the button.

A message may be displayed asking whether you want to reinitialize the applicomIO® interface before starting the detection.


• If you choose "Yes", the applicomIO® interface is initialized immediately with a minimum configuration.

• If you choose "No", the current configuration will be used to carry out the detection.

• Then select an IP address range to be scanned by specifying start and end addresses.

As soon as network detection starts, the scanning starts for the whole IP address range.

The equipment detected can be included in the configuration with the menu command

“Network/Insert in the configuration” or with the button.

The devices can also be included individually, by Drag&Drop, from the "Network detection” tab to the configuration area.


1 : Automatic detection of equipment present


Manual Configuration

Choose the “Equipment library” tab in the resources area.

Select the "Generic Modbus" device.

Drag&Drop the device, from the resource area to the configuration area, or use the insert in the

configuration button


Properties of the device to be inserted in the configuration

When a device is inserted in the configuration, the "General configuration" tab of the "Generic Modbus" 1 device is automatically displayed.

In manual configuration mode, you must specify the device IP address, whereas in automatic mode, the IP address is already completed.

You must then define exchange blocks 2,3 for each device, for the inputs/outputs ("Input" and "Output" tab) irrespective of the configuration mode.

To add this new device to the configuration, press "OK".

You can add up to 128 devices.


1 : Modbus on Ethernet device properties


2 : Purpose of an Exchange block

3 : Configuring the period of an Exchange block

Properties of the master in the configuration

In the "configuration area", display the properties of the Modbus on Ethernet master by double clicking on the Ethernet node

Configure the channel by double clicking on the TCP/IP node (or by pressing the SPACE bar) in the configuration tree

You can now modify the master IP address, the gateway IP address and the network mask.


1 : Properties of the Modbus on Ethernet master


Downloading the configuration

After configuring the Modbus on Ethernet master, adding and configuring the devices of your network, you can download your configuration into the board with the "PcInitIO" 1 command.

This command can be executed in the console with the menu command "File/Board initialization"

or with the button of the main toolbar on the console.


1 : Initialization


7. Tests and diagnostics

On line actions

This feature allows you to read or write 1 data in a Modbus on Ethernet device connected to your network even if this device is not included in the configuration in the applicomIO® console.


1 : Online action on the Modbus on Ethernet network: Description

The diagnostic tool

After configuring the Modbus on Ethernet master, adding and configuring the devices of your network and downloading your configuration in the board, the statuses of all devices can be tested with the diagnostic tool 1.

Start this tool with the menu command “Protocol/Diagnostic…” or with the button.


1 : Implementation: Tests and diagnostics

applicomIO® 2.2 Modbus Ethernet Tests and diagnostics • 33

Diagnostic of the Modbus on Ethernet channel

The Modbus on Ethernet channel diagnostic information can be displayed by selecting the MULTI-MSG ETH channel.

All devices in the configuration are visualized by a LED corresponding to the applicomIO® device number. The LED may be red or green depending on the device error status.

34 • Tests and diagnostics applicomIO® 2.2 Modbus Ethernet

Diagnostic of the TCP/IP layer

This screen is used to display the exchange statuses regarding the TCP/IP layer.

IP address IP address of the applicomIO® master on this channel.

Gateway IP address of the gateway.

The addresses are those configured in the "General" tab of the TCP/IP node.


1 : TCP tab

2 : IP tab


TCP tab

Passive connections Number of passive connections.

Active connections Number of active connections.

Current connections Number of current connections.

Bytes received Number of bytes received

Bytes transmitted Number of bytes transmitted.

Retries on time-out Number of retries on reception of a time-out.


IP tab

Packets received Number of packets received

Packets transmitted Number of packets transmitted

Errors Number of IP errors.


Diagnostic of server devices

Requests Number of requests.

Requests / s Number of requests per second.

Useful bytes Number of useful data bytes.

Useful bytes / s Number of useful data bytes per second.

Requests in error Number of requests in error.


Global diagnostic

View the diagnostic information on a device in the configuration by selecting the node which corresponds to the device:

Requests Number of requests.

Requests / s Number of requests per second.

Useful bytes Number of useful data bytes.

Useful bytes / s Number of useful data bytes per second.

Connections Number of connections created for this device.

Time-out errors


Number of time-outs received for this device.

Frame errors Number of frame errors for this device.

Refusal errors Number of errors excluding time-out and frame errors.


Diagnostic of an exchange block

The information available for an exchange block can be viewed by selecting the exchange block in the tree.

Period ms Exchange block refresh period in milliseconds.

Function Exchange type.

Mode Exchange mode. Either "Cyclic" or "Cyclic and Change Of State".

Nr Var Number of variables read or written.

Address Variable address in the equipment.

Status


Exchange status for this block.


8. Status

General

The various applicomIO® functions return a status word to:

Guarantee the quality of the request.

Diagnose the cause of a failure.

The meaning of the status word value is detailed in the following tables. As well as the general meaning, “Additional Information” will enable you to orient your diagnosis according to the protocol used.

applicomIO® 2.2 Modbus Ethernet Status • 43

applicomIO status

The "General Status" column corresponds to the statuses you may obtain irrespective of the field bus used.

The "Protocol Status" column corresponds to the additional statuses related to the field bus used.

Status Definition

General Protocol 0 No anomaly detected.

The function was properly executed. 1 Unknown function.

The requested function is not supported. 2 Bad address.

The address for the variable that you are soliciting is incorrect. Additional information: Messaging on TCP/IP Ethernet: Returned by the coupler of the destination device. Access to a variable with a bad address or a number exceeding the PLC area.

3 Bad data. Additional information: Frame content inconsistent.

4 Inaccessible data. Additional information: The physical address does not exist, module does not exist or protected data.

32 Indicates that the parameters passed to the functions are not correct (eg: Number of requested variables too large)

33 Response time-out fault.

Additional information: Device configured but not connected to the network.

Wiring problem, the CPU does not execute the communication blocks, connection not declared or badly declared in the CPU.

Check its status and the wiring. Bad device or gateway IP address. Check that the Ethernet frame format configured in the remote device is

"ETHERNET II". 36 Device not configured.

Define the device configuration with the applicomIO® Console and re-initiate the initialization of the applicomIO® product by running the PcInitIO

45 Non-resident dialogue software. Additional information: Initialize the applicomIO® interface before use by running the PcInitIO

46 Board number not configured, or applicom® master/client function targeting a channel configured as slave/server or vice versa.

47 Targeted applicomIO® card invalid or incorrectly initialized by the function IO_Init

44 • Status applicomIO® 2.2 Modbus Ethernet

49 Queuing time fault. The request could not be sent due to lack of resources (no more communication channels available). This time corresponds to 4 times the value of the time-out for the requests in progress. Increase the value of the "time-out for requests in progress". Increase the maximum number of simultaneous requests on the targeted device.

51 Driver system problem. 55 Response time-out exceeded, message lost.

Additional information: Time-out exceeding the value of the "time-out for requests in progress", connection set up, question acknowledged but no answer.

Check the device status. 59 Protection key missing on the applicom® interface.

Use of applicomIO® functions without calling the function IO_Init beforehand. 63 Indicates that a communication error has been encountered on serial Port. 66 Not enough applicomIO® interface memory. 66 Not enough applicomIO® interface memory.

Additional information: Insufficient resources for additional connection.

70 Connection ended by the remote device Additional information: Connection abandoned due to connection problem. Wiring problem, CPU stopped, the CPU does not execute the communication blocks. The targeted device does not support this messaging.

Check the device status. 93 Driver cannot be accessed. 99 Indicates that applicomIO® solution is already running. 255 Indicates that the local input buffer was not updated beforehand by the function

IO_RefreshInput.

applicomIO® 2.2 Modbus Ethernet Status • 45

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Modbus on Ethernet