modbus driver for idaq · modbus for idaq is a component for idaq that reads and writes data with...

ModBus Driver for

iDaq

User guide

March 2020

Rev 2.0

ModBus iDaq Component – User Guide

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TOOLS for SMART MINDS

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Worldwide technical support and product information:

www.toolsforsmartminds.com

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Via Padania, 16 Castel Mella 25030 Brescia (Italy)

Copyright © 2020 TOOLS for SMART MINDS. All rights reserved.

http://www.toolsforsmartminds.com/


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SUMMARY Overview ............................................................................................................................................................................. 5

Introduction ........................................................................................................................................................................ 5

Requirements ..................................................................................................................................................................... 6

Minimum hardware requirements ............................................................................................................................. 6

Minimum software requirements .............................................................................................................................. 6

Installation .......................................................................................................................................................................... 7

Getting started with ModBus devices ................................................................................................................................ 9

Adding a ModBus device to the list of active devices ..................................................................................................... 9

TCP(Ethernet) communication ................................................................................................................................. 11

Serial communication ............................................................................................................................................... 11

ModBus capabilities ...................................................................................................................................................... 13

General Capability Settings ....................................................................................................................................... 14

Handshake Settings .................................................................................................................................................. 15

Text Acquisition/Generation Configuration .............................................................................................................. 20

Reboot Settings ............................................................................................................................................................. 22

Advanced Settings ........................................................................................................................................................ 23

Start-Up Channel Configuration ............................................................................................................................... 24

ModBus channel management ..................................................................................................................................... 26

Channel creation ....................................................................................................................................................... 27

Further details .................................................................................................................................................................. 41


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OVERVIEW iDaq supports installation of additional components to extend capabilities and features of

iDaq itself. With additional components, new types of acquisition devices, new signals

processing features, and other kinds of functionalities can be added to iDaq.

ModBus Driver is a component for iDaq that provide ModBus communication from any

standard Ethernet or serial port.

INTRODUCTION The ModBus protocol follows a master and slave architecture where a master transmits a

request to a slave and waits for the response. This architecture gives the master full control

over the flow of information, which has benefits on older multidrop serial networks.

ModBus manages the access of data simply and flexibly. Natively, ModBus supports two

data types: Boolean value and unsigned 16-bit integer; they correspond to coil and register

ModBus memory block, respectively.

ModBus for iDaq is a component for iDaq that reads and writes data with ModBus slave

devices connected through either an Ethernet or a serial connection.

ModBus component has the following features:

• Signals acquired from ModBus devices are managed by iDaq in the same way as

DAQ-mx devices.

• Read and write access.

• Driver supports both coil and register memory blocks.

• Ethernet and serial communication are supported.

• No special skills are required to acquire data from ModBus devices.

• Quick setup.


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REQUIREMENTS This section contains the list of requirements that users should know before using ModBus

component for iDaq.

M INIMUM HAR DW AR E R EQ UIR EMENT S

Ensure that your computer fulfills the following hardware requirements:

• Dual core CPU or higher.

• 2 GB RAM (4 GB is strongly recommended).

• Display resolution 1900x1080 or higher.

• Mouse or another pointing device.

• A ModBus slave device.

M INIMUM SO FTW ARE R EQ U IR EMENT S

Ensure that your computer fulfills the following software requirements:

• OS: Windows 7 or higher.

• National Instruments Drivers rel. 14.5 or higher. You can download a free copy of

DAQ-mx drivers at the following URL:

http://www.ni.com/nisearch/app/main/p/bot/no/ap/tech/lang/it/pg/1/sn/catnav:

du,n8:3478.41.181.5495,ssnav:ndr/

• iDaq 2016 Edition or higher. You can download an evaluation copy of iDaq at the

following URL:

http://www.idaq-datalogger.com

http://www.ni.com/nisearch/app/main/p/bot/no/ap/tech/lang/it/pg/1/sn/catnav:du,n8:3478.41.181.5495,ssnav:ndr/

http://www.ni.com/nisearch/app/main/p/bot/no/ap/tech/lang/it/pg/1/sn/catnav:du,n8:3478.41.181.5495,ssnav:ndr/

http://www.idaq-datalogger.com/


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INSTALLATION To install ModBus Driver for iDaq, run iDaq, open Configuration Settings Palette and

click on Install a new Device Driver or iDaq Component button as indicated in figure

below.

FIGURE 1 - INSTALLING A NEW COMPONENT FOR IDAQ

Browse your files in File Explorer and select the component file (ModBus_x.x.x.zip). Once

file is selected, iDaq will automatically install it and it will show a successful installation

message. You can check if ModBus Driver for iDaq component for iDaq is installed on your

computer by opening List of Installed Drivers and Extensions in the Configuration

Settings Palette as indicated in figure below.

FIGURE 2 - CHECKING INSTALLED DRIVERS AND EXTENSIONS

As shown in the following figures, if the installation process has been successfully

completed, ModBus, ModBusAnalogAcquisition, ModBusDigitalAcquisition,

ModBusAnalogGeneration, ModBusDigitalGeneration, ModBusAnalogChannels,


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ModBusChannel, and ModBusDigitalChannel are listed among the installed components. If

the installation process has not been successfully completed, an error will appear.

FIGURE 3 - INSTALLING MODBUS DRIVER FOR IDAQ

Once installation is completed, you can start to use your ModBus devices with iDaq.


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GETTING STARTED WITH MODBUS DEVICES This section explains how to add, configure and use a ModBus device with iDaq.

ADDING A MODBUS DEVICE TO THE LIST OF ACTIVE DEVICES To add a new ModBus Device to the list of active devices, open the iDaq main window and

select Add a new device button, as shown in the figure below.

FIGURE 4 - ADDING A NEW MODBUS IN IDAQ

A new dialog window shows the icons of available devices you can use in iDaq to acquire

data. Please note that the list of device icons may be different from the image below,

according to the number of components are installed.

FIGURE 5 – DEVICE TYPE SELECTION WINDOW


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From this window, click on ModBus Device icon and press OK button. The following

window appears.

FIGURE 6 - MODBUS DEVICE EDITOR

ModBus Device Editor shows the list of all created devices[1]. For each device, the following

details are shown:

• Device name. This name must be unique because iDaq cannot manage two devices with the same name.

• Type. It specifies the communication type: Ethernet(TCP) or Serial

• Resource. If current ModBus device uses an Ethernet connection, this field corresponds to the IP address of the ModBus slave. Otherwise, if current ModBus device uses a serial connection, this field corresponds to the COM name of the ModBus slave (i.e. COM1, COM2, COM3).

• File Path of device file, typically stored into c:\iDaq\DeviceCFG\ModBus folder.

To add an existing device, highlight its row in device table and press OK button. It will be

added to the list of active devices and the last-used settings are loaded.

To add a new ModBus device, press Add Button [3]. The following dialog appears:

FIGURE 7 - CREATING A NEW MODBUS DEVICE

As reported by the previous figure, you should type the following information:

1. New device name. Please note that the device name is used as file name and a

subset of chars only is allowed (A..Z,a..z,0..9, space and '_')

2. Communication type. It can be TCP (Ethernet connection) or serial.

After this first selection, you will be prompted to edit communication details (view sections

TCP(Ethernet) communication and Serial communication).

For help, click on Shows Getting Started PDF [2] to view a guide to start using Modbus

driver.


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TCP(ET HERN ET) CO MMUNI CATION

The following figure shows the TCP Communication Editor:

FIGURE 8 – TCP COMMUNICATION EDITOR

The TCP Communication Window is composed of:

1. IP Address. It is the IP address of the ModBus slave.

2. Test button. If pressed, iDaq tries to establish a ModBus connection with the specified

IP address.

SERI AL COMMUNI CATIO N

The following figure shows the Serial Communication Editor:

FIGURE 9 – SERIAL COMMUNICATION EDITOR

Referring to the previous image, the TCP Communication Window is composed of:

1. COM. It specifies the resource you want to open.

2. Baud rate. It specifies the baud rate of the ModBus slave with which you want to

communicate. The ModBus slave can be a ModBus device you create or a third-party

ModBus device. If you want to communicate with a third-party ModBus slave, check

the documentation for the ModBus slave to find its baud rate. The default is 9,600.

3. Unit ID. It specifies the identification of the ModBus slave with which you want to

communicate. The ModBus slave can be a ModBus slave you create or a third-party

ModBus slave. If you want to communicate with a third-party ModBus slave, check the

documentation for the ModBus slave to find its unit ID.

4. Serial type. It specifies the type of data transmission through serial ports:

• RTU (default) uses the Remote Terminal Unit (RTU), which is a binary data

unit, to send data.


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• ASCII uses human-readable characters to send data.

5. Parity. It specifies the parity of the ModBus slave with which you want to



documentation for the ModBus slave to find its parity.

• None specifies to use no parity bit. If you specify None for parity, the number

of stop bits indicating the end of a frame is 2.

• Odd specifies to use odd parity. If you specify Odd for parity, the number of

stop bits indicating the end of a frame is 1.5.

• Even specifies to use even parity. If you specify Even for parity, the number of

stop bits indicating the end of a frame is 1.5.

6. Flow control. It specifies the flow control of the ModBus slave with which you want to



documentation for the ModBus slave to find its flow control.

• None does not use flow control. The transfer mechanism assumes buffers on

both sides of the connection to be large enough to hold all data transferred.

• XON/XOFF uses the XON and XOFF characters to perform flow control. When

the receiving buffer is almost full, the transfer mechanism controls the input

flow by sending XOFF. When the buffer receives XOFF, the transfer

mechanism controls the output flow by suspending transmission.

• RTS/CTS uses the RTS output signal and the CTS input signal to perform flow

control. When the receiving buffer is almost full, the transfer mechanism

controls the input flow by unasserting the RTS signal. When the buffer

unasserts the CTS signal, the transfer mechanism controls the output flow by

suspending the transmission.

• XON/XOFF and RTS/CTS uses the XON and XOFF characters, the RTS output

signal, and the CTS input signal to perform flow control. When the receiving

buffer is almost full, the transfer mechanism controls the input flow by

sending XOFF and unasserting the RTS signal. When the buffer receives XOFF,

the transfer mechanism controls the output flow by suspending transmission.

• DTR/DSR uses the DTR output signal and the DSR input signal to perform flow

control. When the receiving buffer is almost full, the transfer mechanism

controls the input flow by unasserting the DTR signal. When the buffer

unasserts the DSR signal, the transfer mechanism controls the output flow by

suspending the transmission.

XON/XOFF and DTR/DSR uses the XON and XOFF characters, the DTR output

signal, and the DSR input signal to perform flow control. When the receiving

buffer is almost full, the transfer mechanism controls the input flow by

sending XOFF and unasserting the DTR signal. When the buffer receives XOFF

and unasserts the DSR signal, the transfer mechanism controls the output flow

by suspending transmission.

3. Test button. If pressed, iDaq tries to establish a ModBus connection with the specified

connection setup.


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MODBUS CAPABILITIES As shown in the following figure, to edit settings of a ModBus device, open Device &

Sensors tab and click on the device icon, ModBus device editor will be displayed as

indicated in following figure.

FIGURE 10 – MODBUS DEVICE EDITOR

ModBus devices has several capabilities:

• Analog acquisition. It is used to create analog input channels starting from ModBus

register memory block.

• Digital acquisition. It is used to create digital input channels starting from either

register or coil ModBus memory block.

• VCC. It allows the definition of virtual channels calculated from analog real

channels.

• Analog generation. It is used to write ModBus register starting from analog output

channels.

• Digital acquisition. It is used to write ModBus register starting from digital output

channels.

Referring to the previous figure, ModBus device editor is composed of the following

elements:


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1. Analog acquisition. It allows the management of common properties. For more

details view section General Capability Settings.

2. Channel editor (Analog input). It allows the management of analog input

channels.

3. Digital acquisition. It allows the management of common properties. For more


4. Channel editor (Digital input). It allows the management of digital input channels.

5. Virtual Channel editor. It allows the management of virtual channels.

6. Analog generation. It allows the management of common properties. For more


7. Channel Editor (Analog Output). It allows the management of analog output

channels.

8. Digital generation. It allows the management of common properties. For more


9. Channel Editor (Digital Output). It allows the management of digital output

channels.

10. Actual Status. It shows the state of the driver, for example initialization or running.

11. Product page.

12. Device Custom Description. It shows the custom description, if any. Click on it to

add a description or to edit.

13. Reboot settings. For more details view section Reboot Settings.

14. Advanced settings. For more details view section Advanced Settings.

15. Add optional capability. It allows to add capabilities inside the device. It is

required to be used by an expert user.

16. Device reboot.

17. User guide.

Please note that channel configuration is independent from the communication type in use

(TCP or Serial).

GENERAL CAPABILITY SETTINGS General Capability Settings are available from the device editor, for the following

functionalities:

• Analog acquisition;

• Digital acquisition;

• Analog generation;

• Digital generation.

Each of the capabilities listed above has its own editor to configure the related handshakes

and texts.


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FIGURE 11 GENERAL CAPABILITY SETTINGS EDITOR

Referring to the previous figure, General Capability Settings editor is composed of the

following elements:

1. Handshake Settings. It allows the management of Handshake Settings. Enable “Use

handshake during reading operations” for analog and digital acquisition or “Use

handshake during writing operations” for analog and digital generation. For more

details view section Handshake Settings.

2. Text Acquisition Configuration. It allows management of text acquisition/generation

settings.

HAN DS HAK E SET TIN GS

Handshake settings are available in the General Capability Settings.

The handshake functionality changes depending on whether it is an acquisition or

generation capability.

HA N D S H A K E F U N C T I O N A L I T Y F O R AN A L O G A N D D I G I T A L A C Q U I S I T I O N

In the acquisition capability (analog and digital acquisition), the handshake channel is

written periodically. It is used to send periodic commands to the ModBus device to

which it is connected to force the ModBus registers to be updated, for example.

HA N D S H A K E F U N C T I O N A L I T Y F O R AN A L O G A N D D I G I T A L G E N E R A T I O N

In generation capabilities (analog and digital generation), the handshake channel is

used to notify the connected ModBus device that a write operation has been

performed. The handshake channel is written every time a write operation is

performed.

Handshake settings are shown below.


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FIGURE 12 HANDSHAKE SETTINGS IN GENERAL CAPABILITY SETTINGS EDITOR

Referring to the previous figure, handshake settings are composed of the following

elements:

1. Use handshake during reading/writing operations. If enabled, it uses handshake

during reading or writing operations, according to the functionality in which the

property management is located: acquisition or generation.

2. Value to write. It specifies the value to write in the ModBus registers used as

handshake.

3. Handshake Period. It is only supported by acquisition capabilities. It represents the

writing rate of the handshake channel.

4. Waiting time before writing. It is only supported by generation capabilities. It specifies

the delay time between writing any channel and writing the handshake channel. It is

expressed in seconds.

5. Reset handshake after writing. If enabled, it resets to 0 the handshake channel

previously written.

6. Waiting time before reset the handshake. If the previous element is enabled, it

specifies the waiting time between writing the handshake channel and its reset. It is

expressed in seconds.

7. Handshake Channels Configuration. It allows definition and configuration of

handshake channels, which is described below.


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HA N D S H A K E C H A N N E L S C O N F I G U R A T I O N

Handshake Channels list is available from the handshake settings in General Capability

Settings editor (Handshake Channels Configuration button).

FIGURE 13 HANDSHAKE CHANNELS LIST

Referring to the previous figure, the list of handshake channels is composed of the

following elements:

1. List of handshake channels. It shows the list of the available handshake channels,

the registers and the address set.

2. Add. Use this button to add a new element to read/write.

3. Edit. Use this button to edit selected text element.

4. Remove. Use this button to remove selected text elements.

5. Remove All. Use this button to remove all text elements in the list.

From this window, by clicking Add or Edit buttons, it is possible to configure a handshake

channel, as shown in the following figure.


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FIGURE 14 CONFIGURE HANDSHAKE CHANNEL

Referring to the previous figure, the editor to configure handshake channel is composed of

the following elements:

1. Name.

2. Min value. It is the minimum expected value for current channel.

3. Max value. It is the maximum expected value for current channel.

4. Units. It is the unit expected for current channel.

5. Res. Prefix. It is the prefix used to build the channel resource name. It is an advanced

option for advanced users only.

6. IP Address. It specifies the IP Address of the physical device.

7. Register Address. It indicates the register address.

8. Number of Registers. It indicates the number of registers associated to current

channel. It allows the acquisition of signals that are codified on more than one register.

9. Memory Block. It indicates the type of memory to access: Input Register or Holding

Register.

10. Read Mode:

• 2 Bytes. Both register bytes may be written. If 2 Bytes is selected, Bit number may

refer to any bit from 0 to 15.

• 1 Byte High. The highest byte only may be written. If 1 Byte High is selected, Bit

number may refer to any bit from 0 to 7


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• 1 Byte Low. The lowest byte only may be written. If 1 Byte Low is selected, Bit

number may refer to any bit from 0 to 7.

11. LSB/MSB (Most significant byte/Less significant byte). ModBus register data are

unsigned 16 bit values. If LSB is used, bytes are swapped before writing them in the

register; vice versa, if MSB is used, byte order remains unchanged.

12. Conversion. It represents how data is encoded. Supported conversions are:

• None. It does not do any conversion of data.

• Use sign bit. It uses the first bit as sign. 1 = negative; 0 = positive.

• Float. It converts the 32-bit data in float according to the standard IEEE 754.

• To signed integer. It uses 2-complement conversion.

13. Rescale data. If enabled, data is processed as follow: Data x Multiplier / Divider +

Offset. This can be useful to direct convert read data into a physical quantity.

14. Multiplier. It is used only if Rescale data is enabled.

15. Divider. It is used only if Rescale data is enabled.

16. Offset. It is used only if Rescale data is enabled.

17. Use Single Bit. If enabled, a specific bit is used to define value of current channel.

18. Bit number. It specifies the bit to use. It is 0-based.

19. Test Value. It is the value used for channel test. It is available only for analog and digital

generation funcions.

20. Test button. Use this button to test the channel.

21. Group. Use this to assign a group for the channel.

22. Waveform Processing Unit (WPU). WPUs are tools designed for signal processing:

further details are included in the Waveform Processing Unit user guide.


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TEXT ACQUI SITION /GENERATION CON FI GUR ATION

Text Acquisition/Generation Configuration is available from the General Capability

Settings, as reported below.

FIGURE 15 TEXT ACQUISITION/GENERATION CONFIGURATION IN THE GENERAL CAPABILITY SETTINGS

EDITOR

FIGURE 16 TEXT ACQUISITION/GENERATION CONFIGURATION EDITOR

As reported by the figure above, Text Acquisition/Generation Configuration editor is

composed of:

1. Text List. It shows the assigned name to the text, the type of registers and the used

address.

2. Add. Use this button to add a new text element to read/write. For more details view

section Adding a new text element to read/write.

3. Edit. Use this button to edit selected text element.

4. Remove. Use this button to remove selected elements.

5. Remove All. Use this button to remove all the text elements in the list.


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AD D I N G A N E W T E X T E L E M E N T T O R E A D /W R I T E

To add a new text element to read/write, click on the Add button in the Text Acquisition

Configuration editor.

FIGURE 17 EDITOR TO ADD A NEW TEXT ELEMENT TO READ/WRITE IN ANALOG ACQUISITION

As reported by the figure above, editor to add a new text element to read/write is

composed of:

1. Name.

2. Memory block. It specifies the type of memory to access: Input Register or Holding

Register.

3. Number of char per register. It specifies the number of characters to read/write for

each register (1 or 2).

4. LSB/MSB (Most significant byte/Less significant byte). ModBus register data are

unsigned 16 bit values. If LSB is used, bytes are swapped before writing them in the

register; vice versa, if MSB is used, byte order remains unchanged.

5. Start Address. It specifies the first register from which the data is read.

6. Number of Chars. It specifies the number of characters to read/write.

7. Test string (available only for analog generation). It is the text string used for test. It is

available only in the editor to add a new text element to write in analog generation.

8. Test. Use this button to test the channel.


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REBOOT SETTINGS Reboot Settings are available from the device editor.

FIGURE 18 REBOOT SETTINGS EDITOR

As reported by the figure above, Advanced Settings editor is composed of:

1. Validation Delay. It specifies time that must elapse without errors from Device Boot to

confirm that device is working properly. iDaq in fact waits a certain time from when you are

connected to say that the device is really working in order to avoid doing SPAM emails with

connection error/success emails. During this validation time, the data must arrive from the

device and there must be no communication errors.

2. Reboot Automatically in case of Failure. If checked, it enables automatic reboot in case

of disconnection.

3. Reboot Trials before Notification. It specifies the number of consecutive reboot trials

before iDaq notification of “device disconnected”.

4. Refer to Calendar Work Time. If checked, iDaq refers to Calendar Work Time to Reboot

device when is not responding. To set a work calendar, iDaq needs to connect to the

database of the application “Digital Factory 4.0 Calendar”. To set work calendar, from the

main panel select: Configuration Settings > iDaq Option. For more details, please refer to

the iDaq Device Manager User Guide.

5. Max Consecutive Trials. It specifies the number of consecutive reboot trials. After these

trials, the device remains disconnected.

6. Delay Before Consecutive Reboots. It specifies the delay between two consecutive

reboot trials.

7. Indicator of empty email address. If it visible, it means email address list is empty, so no

notification can be sent.

8. Email addresses list configuration. It allows the management of email addresses to send

reboot notifications to.


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ADVANCED SETTINGS Advanced Settings are available from the ModBus device editor.

FIGURE 19 ADVANCED SETTINGS EDITOR

As reported by the following figure, Advanced Setting editor is composed of:

1. Communication type. It can be TCP (Ethernet connection) or serial.

Communication type can be changed even after the creation of the iDaq ModBus

device. For more details, view sections TCP(Ethernet) communication and Serial

communication.

2. Resource. It shows IP address or serial resource according to the communication

type in use.

3. Timeout. It specifies the read/write operation timeout and it is expressed in

milliseconds.

4. Delay between consecutives reads. It specifies if the iDaq component must wait

for a specific time between two consecutive read requests. Default value is 0.

5. Connection attempts. It specifies the number of consecutives reconnection

attempts. Overcome this value, ModBus device returns an error and stops.

6. Read Period. It specifies the acquisition rate, i.e. how often it reads on the device.

The value applies for all types of signals, both analog and digital, and it is

expressed in milliseconds.

7. Optimize Read. If enabled, the driver reads all the necessary records at once. In

particular, in a single read operation it accesses contiguous registers from the

lowest to the highest address used by user-configured channels. For example, if

you have configured 3 channels associated with addresses 5, 20 and 15

respectively, the ModBus driver reads all contiguous registers from 5 to 20, then

extracts the values from registers 5, 20 and 15 to define the values of the

respective channels. Usually this method is faster, but not all devices support it. If


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not enabled, the driver reads only the necessary data, one to one. Usually this

method takes longer.

8. Check Ping before connection. If enabled, the driver pings the hardware to check

if it is available. If there is no response, the connection is not made.

9. Configure Start-up channel List. It allows to configure channels to write at every

start-up of the device. For more details, view section Start-Up Channel

Configuration.

10. Export channels to a CSV file. It allows to export all channels defined in all

capabilities to a CSV file.

11. Communication editor. It shows the communication editor according to the

communication type in use (TCP or Serial). For more details, view sections

TCP(Ethernet) communication and Serial communication.

STAR T-UP CHANN EL CONFI GUR ATION

Start-Up Channel List is available in Advanced Settings Editor, and it is shown in the

following figure. It allows to write configured channels at every start-up on the device. This

feature is useful when, for example, you need to initialize the ModBus device before

proceeding with the acquisition.

FIGURE 20 - EMPTY START-UP CHANNEL LIST

Start-Up Channel List is composed of the following elements:

1. List of Start-Up Channels. The list shows the name of the channels, the resource and the value to write at start-up.

2. Add. It allows to add a channel.

3. Remove. It allows to remove selected channels in the list.


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To add a new channel click on Add and select the channel to be added in the list of start-up

channels. You can choose from any of the previously configured generation channels.

Figure of the list is shown below.

FIGURE 21 - CHANNEL SELECTION

Click again on Add button. The following window will appear.

FIGURE 22 - CONFIGURING VALUE TO WRITE IN THE SELECTED CHANNEL

Insert the value to write in the text box and click again on Add button.

The set channel will appear in the list, as shown below.

FIGURE 23 - CONFIGURED CHANNEL IN START-UP CHANNEL LIST

Repeat the process for every channel to configure.


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MODBUS CHANNEL MANAGEMENT At first use, the lists of analog/digital input/output channels are empty. Channels must be

created starting from registers and coils of the ModBus slave. Each channel is related to a

specific memory element:

• Input Register. It is used to define analog and digital input channels.

• Coils. It is used to define digital input and digital output channels.

• Holding Register. It is used to define analog and digital output channels. The following figure shows the Channel Editor for analog input channels; editors of other

channel lists are similar.

FIGURE 24 - CHANNEL EDITOR (ANALOG INPUT)

Referring to the previous figure, the Channel Editor is composed of the following elements:

1. Channel list. It is the list of defined channels. For each channel, value, physical

resource, ModBus address and channel type are reported.

2. Add single channel button. Use this button to add a single channel. For more details,

view the section

3. Channel creation.

4. Quick channel creation procedure. This button allows the creation of more channels

starting from a specific ModBus address. This procedure allows you to create more

channels in one shot.

5. Edit button. Use this button to edit the channel highlighted in the list.

6. Remove button. Use this button to delete the channel highlighted in the list.

7. Remove All button. Use this button to delete all the channels in the list.

8. Export channel list. Use this button to export channel list and the configuration of

each channel to a csv file.

9. Import channel list. Use this button to import channel list from a csv file.

10. Edit Waveform Processing Unit (WPU) for the selected channels. WPUs are tools

designed for signal processing: further details are included in the Waveform Processing

Unit user guide.

11. Edit custom channel attributes. Use this button to edit custom channel attributes for

the selected channels.


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12. Edit Group Attribute for selected channels. Use this button to edit Group Attribute for

the selected channels.

CHANN EL CR EATION

As reported before, ModBus driver supports two different ways to create channels:

1. Single channel creation.

2. Quick channel creation.

S I N G L E C H A N N E L C R E A T I O N – A N A L O G I N P U T

To create a single analog input channel, press Add single channel button from the Channel

Editor (Analog Input Capability). The following window will appear.

FIGURE 25 ADD SINGLE CHANNEL PROCEDURE

Elements in this window are:

1. Channel name.

2. Min value. It is the minimum expected value.

3. Max value. It is the maximum expected value.

4. Units. It specifies the unit of measurement.

5. Res. Prefix. It is the prefix used to build the channel resource name. It is an

advanced option for advanced users only.



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7. Register Address. It specifies the ModBus input register address used to

created current channel (data read from this address will be used to define

values of the current analog input channel).

8. Number of registers. It indicates the number of registers associated to current

channel. It allows the acquisition of signals that are codified on more than one

register.

9. Memory block. It specifies the type of memory to access to acquire data.

10. Read Mode:

• 2 Byes: both register bytes are used to build the analog signal.

• 1 Byte High. The high byte only is used to build the analog signal.

• 1 Byte Low. The low byte only is used to build the analog signal.

11. LSB/MSB (Most significant byte/Less significant byte). Data acquired with

ModBus are unsigned 16 bit values. If LSB, is used, read bytes are swapped;

vice versa, if MSB is used, byte order remains unchanged.




• Signed integer. It uses 2-complement conversion.

• Float. It converts the 32-bit data in float according to the standard IEEE

754.

Not all conversion types are available for all data types. This field is not

available if selected Data type is Bit.

13. Rescale data. If enabled, data is processed as follow: Data x Multiplier /

Divider. This can be useful to direct convert read data into a physical quantity.




17. Use single bit. If enabled, it extracts a single bit (from 1 to 16).

18. Bit number. It specifies the bit number to extract. If it’s 0, it extracts the first

bit.



21. Waveform Processing Unit (WPU). WPUs are tools designed for signal

processing: further details are included in the Waveform Processing Unit user

guide.

After confirmation, a single channel is created, and it is added to the channel list of the

Channel Editor (Analog Input Capability).


29

Q U I C K C R E A T I O N - A N A L O G I N P U T

This mode allows the creation of more channels starting from a specific ModBus address.

This procedure allows you to create more analog input channels in one shot. To create

channels in this way, press the Quick channel creation button from the Channel Editor. The

following window will appear.

FIGURE 26 QUICK CHANNEL CREATION


1. Base Name. it is the base name used to build channels names.



4. Units. It is the unit expected for current channels.

5. Register Address. It specifies the ModBus input register address used to

created current channels (data read from this address will be used to define

values of the current analog input channels).

6. Number of channels. It specifies the number of channels to be created.

7. Number of Registers per channel. It indicates the number of registers

associated to current channel. It allows the acquisition of signals that are

codified on more than one register.

8. Address preview. It shows the preview of used addresses.

9. Read Mode:


30











754.






15. Test button. Use this button to test channels.

If you specify 5 as number of channels, 15 as register address, and Channel as channel base,

the following five channels will be created:

• Channel _0 – index: 15






31

S I N G L E C H A N N E L C R E A T I O N – D I G I T A L I N P U T

To create a single digital input channel, press Add single channel button from the Channel

Editor (Digital Input Capability). The following window will appear.



1. Channel name.




1. Memory Block. It specifies the memory block used to defined current channel:

• Input Register

• Holding Register

• Coils

• Discrete Inputs

4. Bit number. It is available only if Register Memory block is selected. As a

register is a 16-bit value, this field specified which bit corresponds to current

digital channel.

5. Register/Coil Address. It specifies the ModBus input register address or the

coil address according to the selected Memory Block.

6. Read Mode:

• 2 Bytes. Both register bytes are used to build the digital channel. If 2

Bytes is selected, Bit number may refer to any bit from 0 to 15.

• 1 Byte High. The highest byte only is used to build the digital channel.

If 1 Byte High is selected, Bit number may refer to any bit from 0 to 7


32

• 1 Byte Low. The lowest byte only is used to build channel signal. If 1

Byte Low is selected, Bit number may refer to any bit from 0 to 7.




8. Test button. Use this button to test current channel.


After confirmation, a single channel is created, and it is added to the channel list of the

Channel Editor (Digital Input Capability)

Q U I C K C R E A T I O N - D I G I T A L I N P U T


This procedure allows you to create more channels in one shot. To create channels in this

way, press the Quick channel creation button from the Channel Editor. The following

window will appear.

FIGURE 28 QUICK CHANNEL PROCEDURE






4. Memory Block. It specifies the memory block used to defined current digital

channel:

• Input Register


• Coils

• Discrete Inputs


33


6. Read Mode:

• 2 Byes. Both register bytes are used to build the digital channel.

• 1 Byte High. The high byte only is used to build the digital channel.

• 1 Byte Low. The low byte only is used to build channel signal.





If you specify 5 as number of channels, 15 as address, Register as memory block, and

Channel as channel base, the following five channels will be created:

• Channel _0 – register address 15 - bit: 0

• Channel _1 – register address 15 – bit: 1




If you specify 5 as number of channels, 15 as address, Coil as memory block, and Channel as

channel base, the following five digital input channels will be created:

• Channel _0 – coil address 15






34

S I N G L E C H A N N E L C R E A T I O N – A N A L O G O U T P U T

To create a single analog output channel, press Add single channel button from the

Channel Editor (Analog Output Capability). The following window will appear.



1. Name.

2. Min value. It is the minimum expected value for current channel.

3. Max value. It is the maximum expected value for current channel.

4. Units. It is the unit expected for current channel.




7. Register Address. It indicates the register address.

8. Number of Registers. It indicates the number of registers associated to

current channel. It allows the acquisition of signals that are codified on more

than one register.

9. Memory Block. It indicates the type of memory to access: Input Register or

Holding Register.

10. Read Mode:

• 2 Bytes. Both register bytes may be written. If 2 Bytes is selected, Bit

number may refer to any bit from 0 to 15.


35

• 1 Byte High. The highest byte only may be written. If 1 Byte High is

selected, Bit number may refer to any bit from 0 to 7

• 1 Byte Low. The lowest byte only may be written. If 1 Byte Low is

selected, Bit number may refer to any bit from 0 to 7.

11. LSB/MSB (Most significant byte/Less significant byte). ModBus register data

are unsigned 16 bit values. If LSB is used, bytes are swapped before writing

them in the register; vice versa, if MSB is used, byte order remains

unchanged.





754.



Divider + Offset. This can be useful to direct convert read data into a physical

quantity.




17. Use Single Bit. If enabled, a specific bit is used to define value of current

channel.

18. Bit number. It specifies the bit to use. It is 0-based.

19. Test Value. It is the value used for channel test. It is available only for analog

and digital generation funcions.



22. Waveform Processing Unit (WPU). WPUs are tools designed for signal

processing: further details are included in the Waveform Processing Unit user

guide.

After confirmation, a single channel is created and it is added to the channel list of the

Channel Editor (Analog Output Capability).


36

Q U I C K C R E A T I O N - A N A L O G O U T P U T


This procedure allows you to create more channels in one shot. To create channels in this

way, press the Quick channel creation button from the Channel Editor. The following

window will appear.






4. Units. It is the unit expected for current channels.

5. Register Address. It specifies the ModBus output register address used to

created current channels.


7. Number of Registers per channel. It indicates the number of registers

associated to current channel. It allows the acquisition of signals that are

codified on more than one register.


9. Read Mode:


37











754.




13. Test value. It is the value used for rescaling data test.




17. Test button. Use this button to test channels.

If you specify 5 as number of channels, 15 as register address, and Channel as channel base,

the following five analog output channels will be created:







38

S I N G L E C H A N N E L C R E A T I O N – D I G I T A L O U T P U T

To create a single digital output channel, press Add single channel button from the Channel

Editor (Digital Output Capability). The following window will appear.



1. Channel name.




4. Memory Block. It specifies the memory block used to defined current channel:

• Input Register


• Coils

• Discrete Inputs

5. Bit number. It is available only if Register Memory block is selected. As a

register is a 16-bit value, this field specified which bit corresponds to current

digital channel.



7. Read Mode:

• 2 Bytes. Both register bytes are used to build the digital channel. If 2

Bytes is selected, Bit number may refer to any bit from 0 to 15.

• 1 Byte High. The highest byte only is used to build the digital channel.

If 1 Byte High is selected, Bit number may refer to any bit from 0 to 7


39

• 1 Byte Low. The lowest byte only is used to build channel signal. If 1

Byte Low is selected, Bit number may refer to any bit from 0 to 7.




9. Test Value. It is the value used for test.



After confirmation, a single channel is created and it is added to the channel list of the

Channel Editor (Digital Output Capability).

Q U I C K C R E A T I O N - D I G I T A L O U T P U T

This mode allows the creation of more digital output channels starting from a specific

ModBus address. This procedure allows you to create more channels in one shot. To create

channels in this way, press the Quick channel creation button from the Channel Editor. The

following window will appear.








40

4. Memory Block. It specifies the memory block used to defined current digital

channel:

• Input Register


• Coils

• Discrete Inputs


6. Read Mode:

• 2 Byes. Both register bytes are used to build the digital channel.

• 1 Byte High. The high byte only is used to build the digital channel.

• 1 Byte Low. The low byte only is used to build channel signal.




8. Test Value. It is the value used for test.


If you specify 5 as number of channels, 15 as address, Register as memory block, and

Channel as channel base, the following five digital output channels will be created:

• Channel _0 – register address 15 - bit: 0





If you specify 5 as number of channels, 15 as address, Coil as memory block, and Channel as

channel base, the following five digital output channels will be created:







41

FURTHER DETAILS iDaq product page: www.idaq-datalogger.com

iDaq ADD-ON Store www.idaq-datalogger.com/en/products

Support: www.idaq-datalogger.com/en/support

ModBus Driver for iDaq product page: https://www.idaq-

datalogger.com/en/products/drivers/modbus-driver-for-idaq

ModBus Driver for iDaq User Guide: https://www.idaq-

datalogger.com/_documents/en/ModBus-User-Guide-2-0.pdf

Getting stated with ModBus Driver for iDaq: https://www.idaq-

datalogger.com/_documents/en/Getting-Started-with-ModBus-2-0.pdf

Introduction to ModBus http://www.ni.com/white-paper/7675/en/

ModBus organization website http://www.modbus.org/

http://www.idaq-datalogger.com/

http://www.idaq-datalogger.com/en/products

http://www.idaq-datalogger.com/en/support

https://www.idaq-datalogger.com/en/products/drivers/modbus-driver-for-idaq

https://www.idaq-datalogger.com/en/products/drivers/modbus-driver-for-idaq

https://www.idaq-datalogger.com/_documents/en/ModBus-User-Guide-2-0.pdf

https://www.idaq-datalogger.com/_documents/en/ModBus-User-Guide-2-0.pdf

https://www.idaq-datalogger.com/_documents/en/Getting-Started-with-ModBus-2-0.pdf

https://www.idaq-datalogger.com/_documents/en/Getting-Started-with-ModBus-2-0.pdf

http://www.ni.com/white-paper/7675/en/

http://www.modbus.org/

modbus driver for idaq · modbus for idaq is a component for idaq that reads and writes data with...

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