Category Archives: number

Horner XL4 Numbering System and Addressing

We will now look at the Horner XL4 numbering system and addressing. Data is stored into different memory type locations called registers. The registers can be either bits or words (16bit). Multiple registers can be used together to store a 32 bit value. (Double word) This all in one controller has several additional registers to handle some of the HMI communication. Let’s look at all of the areas in the controller. Continue Reading!

The 7 Essential Parts of a PLC System

When I was in school PLC’s were just in their infancy. We were taught that the PLC consisted of the central processing unit (CPU), analog and digital inputs and outputs. Everything was programmed with dedicated handheld devices and/or software devices on specialized hardware. We now have modern PLC systems that are capable of so much more. Let’s look at how we can now break up these modern PLC system into the seven essential components.

CPU
Inputs and Outputs (I/O)
Analog I/O
Specialty I/O
Programming Tools
HMI
Networking Continue Reading…

Horner XL4 Installing the Software Cscape

The Horner XL4 OCS all-in-one controller is programmed using Csape. Cscape (Control Station Central Application Programming Environment) This single programming software package is designed to be easy to use and maintain. We will now install this programming package onto our computer. Continue Reading!

Click PLC Send and Receive Instructions

Receive and Send instructions will allow you to send and receive serial data to an external device. The communication method that you setup can be ASCII or Modbus. ASCII (American Standard Communication for Information Interchange) can be used to send to devices such as a printer. Receiving ASCII can be used for connecting barcode scanners to the PLC. The barcode will be read as an ASCII string in the PLC. Modbus serial communication (Modbus RTU) is a standard protocol used in many automation devices. We will demonstrate the Send and Receive instruction by communicating Modbus to a Solo Temperature Controller. Our example will read the current process (PV) value and write the set point value (SV) in the controller.  Keep on Reading!

Click PLC Drum Instruction

Drum instructions are great tools when you have a simple sequence of events that need to occur at a set time interval or as a result of an event. They mimic an electromechanically drum sequencer. The Click PLC has a drum in the instruction set. We will discuss the drum instruction and look at an example of controlling traffic lights.  Keep on Reading!

Click PLC Timers and Counters

Continuing our series, we will now look at timers and counters and how they are used in the Click PLC. Previously we have discussed:
Click PLC System Hardware
Click PLC Installing the Software
Click PLC Establish Communication
Click PLC Numbering System and Addressing
The programming software and manuals can be downloaded from the Automation Direct website free of charge.  Keep on Reading!

Click PLC Numbering System and Addressing

Continuing our series, we will now look at the numbering systems and addressing used in the Click PLC. Previously we have discussed:
Click PLC System Hardware
Click PLC Installing the Software
Click PLC Establish Communication
The programming software and manuals can be downloaded from the Automation Direct website free of charge. These are being used exclusively in our Click PLC series.  Keep on Reading!

AdvancedHMI to Solo Process Temperature Controller

Modbus RTU will be the serial (RS485) method in which we will communicate between the AdvancedHMI Screen and the Automation Direct Solo Process Temperature Controller.
We can address up to 247 (Solo 1 to 247) devices on this master – slave protocol. A maximum of 32 devices (Nodes) on the network can communicate to the master. A review of the Modbus RTU protocol can be seen at the following URL.
http://www.rtaautomation.com/technologies/modbus-rtu/

AdvancedHMI is a free HMI programming package the runs on Microsoft Visual Studio. It can be downloaded at the following URL.
https://sourceforge.net/projects/advancedhmi/

Connections:
We will be running the AdvancedHMI software on the computer. One of the USB ports will have an USB to RS485 adapter and communicate RS485 to the Solo process temperature controller.

See the following post to install the USB to RS485 adapter.
http://accautomation.ca/usb-to-rs485-pc-adapter-installation/

Solo Controller Settings:
In the Initial Setting Mode we will change the on line configuration to on and make the changes to the Modbus settings as follows: 9600 Baud, Even, 7 Data Bits, 1 Stop Bit, Modbus ASCII Format. We will leave the default unit number as 1. See the following post to set the controller:
http://accautomation.ca/solo-process-temperature-controller/

Modbus RTU (Addresses)
The following address will be used in our project:


AdvancedHMI will use the Modbus Decimal value in the PLCAddressValue to determine the information that you want to get. For a list of all Modbus addresses that can be used in your project, refer to the Solo Manual located a the following URL:
https://www.automationdirect.com/adc/Manuals/Catalog/Process_Control_-a-_Measurement/Temperature_-z-_Process_Controllers

Screen Display: (AdvancedHMI)
Here is what our screen will look like:

We have mimicked the look of the solo process temperature controller. Our PV and SV values are DigitalPanelMeters from the AdvancedHMI toolbar.  The eight output indicators are just labels.

Our ModbusRTUCom1 settings are as follows:

Settings: 9600, 8, Even, One StopBit and Station 1 should all match the settings in the Solo process temperature controller that we did previously.
PollRateOverride will allow us to determine how often the communication will take place to the controller. (250msec)
The PortName will be the same port number that the computer will communicate out of. This will be set when you install the USB to RS485 adapter. It may change if a different USB port is used.

The DataSubsciber1 will be used to determine the status of the controller.

PLCAddressValue = 44139

We read the value of the eight status bits and convert this into a string so we can determine the status of each of the individual bits. Here is the code that is used to do this. It is the only code required for this application.

Private Sub DataSubscriber1_DataChanged(sender As Object, e AsDrivers.Common.PlcComEventArgs) Handles DataSubscriber1.DataChanged
        Dim i As Integer = DataSubscriber1.Value
        Dim Status As String
        Status = Convert.ToString(i, 2).PadLeft(8, "0") '8 bits
        'There are 8 bits that we need to check and account for on our screen. 
        'Modbus Decimal - 44139
        'Bit 0 - ALM3 - Alarm 3
        'Bit 1 - ALM2 - Alarm 2
        'Bit 2 - C degrees
        'Bit 3 - F degrees
        'Bit 4 - ALM1 - Alarm 1
        'Bit 5 - OUT 2 
        'Bit 6 - OUT 1
        'Bit 7 - AT - Auto Tuning

The complete AdvancedHMI code for this application can be downloaded at the end of the post.

The PV and SV indicators are DigitalPanelMeters as mentioned above.


They both have four digits with a decimal position of 1. This will give us a value between 000.0 and 999.9.
The SV includes a keypad to change the set value. KeypadScaleFactor is set to 0.1 to allow for the decimal place.

Included in our display is a BasicTrendChart from the AdvancedHMI toolbar.


You want to make sure that the YMaximum and YMinimum settings are set so the values will not go past these settings. If they do then the graph line will disappear from the chart at that point and time.
This will show a running trend for the last 5 minutes.
Polling rate is 250msec x 1200 points in the chart = 300 000msec
300 000msec / 1000 = 300 seconds
300 seconds / 60 (seconds in minute) = 5 minutes

Notes: Displaying Extended ASCII Symbols in Visual Studio (VB.NET)
You can display any symbol in the visual studio environment by holding the ‘Alt’ key down and typing the decimal number of the symbol that you want. In our example the degrees symbol is Alt 248.
Here are the extended ASCII symbols:

http://www.asciitable.com/

Running the Application:

You will notice that the response rate is very quick. (250msec) As the PV, SV or indication values change, the screen will get updated.

The trend chart will show the last 5 minutes of the PV value. 

As you can see, programming the AdvancedHMI to communicate to the Solo process temperature controller is very easily done.

Download the AdvancedHMI code for this project here.

Watch on YouTube : AdvancedHMI to Solo Process Temperature Controller
If you have any questions or need further information please contact me.
Thank you,
Garry



If you’re like most of my readers, you’re committed to learning about technology. Numbering systems used in PLC’s are not difficult to learn and understand. We will walk through the numbering systems used in PLCs. This includes Bits, Decimal, Hexadecimal, ASCII and Floating Point.

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