The Pixel industrial controller is a Segnetics product from the 12xx - 25xx series, which is widely used in practice. Traditionally, these controls are applied to ventilation and air conditioning systems. The Pixel controller itself is purely electronic. Therefore, the device functions only when loaded control program Pixel controller - the core and system design of ventilation or other equipment.
Often, devices are sold pre-programmed for specific equipment. But in practice, one has to deal with different configurations of technical systems.
Control device for industrial ventilation and air conditioning systems, as well as other equipment, fully automatic
Therefore, the practice of Pixel programming always remains relevant. Based on, programming "Pixels" should be divided into two stages:
- System stage (project creation and loading).
- Working phase (parameter programming and startup).
Pixel System Programming
The system stage of programming involves the creation of a working project for Pixel with the subsequent loading of the created code into the module permanent memory controller.
It should be clarified: the downloaded project is an intermediate program code, which is processed by the main program, the Pixel core, during the operation of the controller.
Creation system program to the "Pixel" is carried out through a special service software called SMLogix. The software supports FBD (Function Block Diagram) programming under GUI.
The interface ("pure") of the software package designed to develop a system software under the control of various industrial and economic equipment The SMLogix programming system for Pixel controllers is designed for Windows and can be installed on personal computers without restrictions.
It should be noted that the SMLogix complex is a rather complex service software. The software supports the development of software projects at the level of the methodology for constructing FBD diagrams with the participation of macros. The programming process takes place in the following sequence:
- Are determined specific goals project.
- A paper scheme of the project is being drawn up.
- Based on a paper sketch, an FBD diagram is made.
- The project is being compiled.
- Testing and debugging.
Despite the complexity of the service software, if you wish, you can learn how to program on SMLogix from scratch. But to facilitate the knowledge of all the intricacies of FBD programming, it is recommended to practice on ready-made projects for the Pixel controller.
Such projects are available on the official resource of the manufacturer. A software service package is also available for download. It is advisable to have a “free” (test) Pixel controller on hand.
Examples of developing FBD project blocks
Suppose there is a task to implement the function of a discrete controller to control the heating element. Using the software for Pixel, this function is implemented by creating a block diagram on the working field of the SMLogix program.
This is how a piece of a system program that implements the function of a discrete temperature controller looks like. Heaters can be installed, for example, on air conditioning equipment After compiling and loading into the controller, the generated code acts as follows:
- The setpoint is being processed.
- Boundary temperature points are calculated.
- The heating element is turned on or off.
A characteristic feature here is the smooth dynamics of the operation of the regulator circuit. In practice, such work is marked by a clear operation of the relay. Contact bounce is completely eliminated.
Here, something like this creates a full-fledged control program for the controller and air conditioning, as well as other systems.
A control or monitoring function is programmed for each module. Everything is combined into a single functional diagram and loaded into the controller's memory.
Loading of the finished compiled program is carried out by one of two interface options. The first allows you to download and run, the second supports debugging Downloading a project directly to the Pixel controller's memory is done through the buttons working panel SMLogix. There are two buttons for this purpose. One button activates the function for loading with subsequent start.
The second button activates the function to boot into debug mode. Before downloading, the controller must be connected and made sure that communication is available through the "Diagnostics and Search" option.
By the way, it will be noticed: through the “Diagnostics and Search” option, if necessary, updating the processor core code is carried out.
This is how the “SMLogix” program window looks like, through which programming is performed - updating the core of the Pixel controller This is a completely separate operation, not directly related to loading the project. In addition, the core files have a different extension than the project files.
Pixel programming workflow
"Pixel" at the working stage includes actions to configure the downloaded software project for the existing ventilation and air conditioning system, or other equipment.
The process consists in setting the necessary operating parameters, for example:
- air temperature in the room,
- air pressure at the outlet of the supply system,
- restrictions on the heating of the return heat carrier,
- season of the year,
- time for the timer.
The general list of settings, depending on the configuration of the equipment, can be more than a dozen items. In addition, there are system settings that set The current date, time, baud rate parameters, etc.
Setting parameters is an integral part of working with electronics of this kind. Properly selected settings are the key to trouble-free operation of the equipment The working stage of programming supports the function of copying and loading the project. That is, it is possible, literally at the touch of a button, to copy work program to a removable memory module.
Then the copy is transferred to the "clean" controller and is also loaded with one click of a button. Such a solution dramatically simplifies the mass installation of devices. True, the copy function is supported only on Pixel 25xx models.
Practical video example of creating an FBD Pixel
A demo video example of programming an industrial controller Pixel is a kind of instruction for creating program code followed by implementation in a real device:
In this article, we will consider how you can create a video screen or a ticker from pixels.
Pixels look like:
The pixel size is shown in the drawing below.
Pixels are supplied connected in garlands of 50 pieces.
In each RGB LED module or pixel, there is a control controller.
The chip and the LED itself are embedded in a waterproof, transparent, soft, silicone case. The peculiarity of pixels is that they can be controlled independently of each other, this is provided by a microcircuit inside the pixel. This property allows you to create video screens and tickers based on pixels.
Pixel Specifications:
|
Diode type |
|
|
Number of colors |
32k (LPD6803) or 16M (WS2801) |
|
Mount type |
Through hole Ø12mm, thickness mat. 2-3mm |
|
Degree of protection |
|
|
dimensions |
38mm x 12.5mm x 12.5mm |
|
Maximum current through all three colors |
60mA (0.3W) |
|
Control protocol |
Serial over two wires |
Table of degrees of protection
The degree of protection of the pixels IP67 means that they are completely protected from dust, and also withstand temporary immersion in water up to 1m.
The main advantages of these pixels:1) Low cost
2) High brightness
3) High degree protection IP65
4) Ease of installation (any person can be trained in pixel editing in 10 minutes, therefore, you do not need to hire expensive specialists).
5) Possibility of dismantling and reuse
6) During operation, the pixel does not heat up
The main scope of this type of pixels is:
1) LED full-color dynamic scoreboards and running lines of any shape, for example, a medical cross, a heart.
2) Dynamic logos of any geometry.
3) Using pixels as a dynamic light source to bring design ideas to life.
4) Since the pixel has a simple way of fastening into a hole with a diameter of 12 mm, this makes it possible to install it on any curved surfaces (ball, columns).
Calculation of the required number of pixels to use in the project.
To understand how many pixels you need, and at what distance you need to place them, consider the following:
1) From what distance the image should be visible.
2) What is the size of the image in pixels you want to display.
The distance between pixels is determined based on the following table.
The main rules for choosing a pixel pitch:
15mm comfortable viewing distance over 17 meters,
25mm comfortable viewing distance over 30 meters,
50mm comfortable viewing distance over 60 meters.
Knowing the size of the image in pixels that you want to display, you can calculate the number of pixels needed, for example, if the image size is 32cm x 32cm in 10mm increments, then you need 1024 pixels.
From our experience, a pixel pitch of 20-30mm is comfortable for perception.
Sometimes, in front of the pixels, an additional light-scattering element (matte acrylic sheet) is installed at a short distance to reduce the effect of “dots”.
Also, it is important to think carefully about the content that you plan to display on a scoreboard of managed pixels.
The software for the controller that controls the pixels allows you to insert ready-made AVI, GIF, video animations into the project. various formats and Flash animation created in other editors. This makes it possible to create animations of any complexity.
Electrical connection of LED pixels.
The pixels are connected in series c using a 4-wire cable. Where are the two digital wires serial interface DAT and CLK and two power wires + 5V and minus. Pixels are supplied in the form of garlands of 50 pieces with connectors at the ends.
The maximum installation pitch is 70mm without extension, but it can be increased. To do this, you need to cut the standard cable and extend it to the required distance (up to 1.5 meters).
Below is a diagram of connecting pixels to the controller and power supply.
Connection requirements, in the case of a stand-alone system.
1) Pixels are connected in the form of a continuous garland, up to 2048 pieces long.
2) If the quantity is more than 2048, then a multi-output controller is used, where 2048 pixels can be connected to each digital output.
3) 5V power must be connected every 40-50 pixels, i.e. at the beginning and end of the garland.
4) If the last segment of pixels is less than 25pcs, then the power supply to the end of the garland can not be supplied.
5) If the project uses several power supplies, then at the point where the garland switches to another power supply, the 5V bus is broken, as shown in the figure below
6) The remaining power wires at the end of the last garland must be insulated from each other.
7) If the products are planned to be used outdoors, then it is better to connect the garlands to each other not through connectors, but by soldering and isolate them with a heat shrink tube
8) Be careful, a pixel has an input and an output, signals from the controller are received at the input, and signals from the output go to the inputs of neighboring pixels.
9) The input of the first pixel is connected to the controller only by wires GND, DAT, CLK.
Purpose of pixel wires.
For different models pixels, the color and purpose of the wires may differ. The color of the loop in different batches may also vary.
Power supply power selection
The calculation of the required power of power supplies is based on the number of pixels N multiplied by the maximum pixel power of 0.6W and multiplied by a factor of 1.2
For example, the project uses 1024 pixels, multiply by the maximum pixel power 1024 x 0.6 = 614.4 W and multiply the resulting power by a factor of 1.2, we get 737.28W. We need to use a power supply with this power or more for a voltage of 5V, or we can use several power supplies of lower power, if we take three power supplies, then the power of each should be at least 738/3 = 246W.
Controller selection
From the above, now we can determine how many pixels will be involved in the project. Choice specific model controller depends on the total number of pixels in the project. If up to 2000 pixels, then the CS1 controller is enough. It has one port for connecting pixels. If more than 2000, but less than 4000, then you need to take the CS2 controller, which has two ports, each for controlling 1024 pixels. Etc.
When using multi-port controllers, it is desirable to evenly distribute pixels across ports.
For example:
The project uses 2150 pixels, a CS2 controller is used, which has 2 outputs. Then 1074 pcs will go to the first port, 1074 pcs will go to the second port.
The considered pixels are also called “finger”, they are installed in a hole with a diameter of 12 mm in any material with a thickness of 2-3 mm. The surface can be either flat or curved (arc, cylinder, ball, etc.)
Overall and installation dimensions of pixels
1) LED-pixels are mounted in the form of a continuous garland, with power connected through 40-50 pcs.
2) Holes must be placed in a grid with the same pitch, this will simplify the creation of a program on a PC.
Frequently Asked Questions (FAQ)
Question 1. Is it possible to assemble a video screen (media facade) on these pixels?
Answer. Depending on what you mean by a video screen, you can use these pixels to assemble a full-color scoreboard on which you can play simple animation and flash videos.
It is problematic to assemble a full-fledged video screen with a high refresh rate and a high resolution of more than 240x320.
The controllers offered by us allow you to play an animated video recorded in advance in the controller's memory. This video can be made in any video editor or Flash animation editor and it can contain any graphics, including text.
Question 2. Is it possible to increase the standard distance between pixels.
Answer. Yes, within reason.
Pixels are controlled by digital SPI protocol. This protocol is not immune to electromagnetic interference. Increasing the length between pixels can lead to a complete system failure or periodic "blinking".
A long cable can be affected by various factors:
1) Wire resistance
2) CLK signal frequency. The higher the CLK frequency, the less elongation can be performed.
3) Electromagnetic interference. The presence of a power cable or a transceiver antenna in the immediate vicinity can lead to unpredictable results.
If lengthening is necessary, we recommend the following:
1) Reduce the frequency of the CLK signal to the minimum possible value. Attention: reducing the frequency will reduce the speed of "redrawing" the animation.
2) For extension, use an 8-wire network computer cable with a shield braid. Use 3 wires for power supply, one each for DAT and CLK signals. Connect the shield to negative (GND). Moreover, the DAT and CLK wires must be “twisted” relative to GND separately.
These recommendations are not a complete guarantee of results.
Pixel Controller Features:
- High degree of modularity. You don't have to pay for unused channels or interfaces. To base controller resources Pixel, by connecting additional modules, the following features are added:
- Communication in Lonworks or Ethernet network;
- Increase in input-output channels up to 64;
- Expandable non-volatile memory up to 256K for storing setpoints, events, graphs or trends;
- The use of non-volatile memory type Fram, allowing you to make an unlimited number of entries;
- When adding new modules, there is no need to dismantle the Pixel controller or take it apart. This further simplifies the work during its operation.
- Free programming using the SmLogix tool in combination with the SmConsctructor configuration program, you can quickly create control programs and adapt them to a specific object.
- Full software compatibility with the SMH 2010 controller. No need to re-program. Everything that worked on the SMH 2010 will function similarly on the Pixel controller.
- Full compatibility of Pixel controllers with MasterSCADA SCADA system.
- Ability to save and transfer control programs using memory modules. A computer is not required on site.
- Graphic display of the Pixel controller, which allows you to display graphics and text in various sizes.
Specifications:
Digital inputs
- Quantity - 6 optoisolated inputs
- Operation voltage levels - Closed "dry" contact - from 12 to 36VDC Open "dry" contact - from 0 to 1VDC
Discrete outputs
- Quantity - 2 relay outputs and 1 triac or transistor output, depending on the version
D out - electromagnetic relay
- Switched voltage - Up to 277VAC / 30VDC
- Switched current - Up to 10A
- Switching time - 10ms
- Resource - 100000 switching
D out - triac (with optocoupler)
- Switching voltage - Up to 277VAC / 50Hz
- Switching current - From 10mA to 0.5A
- Cut-off angle adjustment - No
- Resource - Unlimited
D out - Transistor (no optocoupler)
- Switched voltage - Up to 36V DC
- Switching current - Up to 0.5A
- Resource - Unlimited
Analog inputs
- Quantity - 5+1 (without galvanic isolation)
- Type - 5 RTD inputs, 1 current/voltage measurement input
- Connected thermal resistances - Up to 5 Pt1000 sensors; up to two NTC thermistors with a resistance of up to 20 kOm (the number of connected sensors depends on the version)
- Measured voltage/current - 0…10V DC / 0…20mA DC
- Resolution - 10mV / 20 µA (10 digits)
Analog outputs
- Quantity - 2 (without galvanic isolation)
- Range - 0 - 10V DC
- Load capacity - 12mA per channel
- Overload protection - Yes
Food
- Resolution - 18-36VDC, 18-29VAC
- Power consumption - No more than 3.5W
Interfaces
- Serial Port Built-in RS485 (Modbus RTU protocol)
- Network card (optional) - Ethernet 10Mbit or LONWorks
- Keyboard - 5 buttons
- Display - single color 122x32
- Light indication - 2 LEDs
The Pixel controller is designed according to the principle personal computer- you can change its components depending on the needs.
Network cards for the Pixel controller. Removable network cards- the ability to upgrade obsolete equipment.
Extension modules for the Pixel controller. Adding new modules without removing or disassembling the controller. Implemented distribution of addresses, hot pickup, etc. When switching from protocol to protocol, additional programming of the Pixel controller is not required.
Memory module for the Pixel controller. This module is designed for removing archives and for loading working programs into the Pixel controller. Pixel controllers get up to 10x faster to get ready to go.
Pixel controller graphic display. Temperature and humidity trends, simple and clear interface.
Documentation by instrument
Pixel Controller It is arranged on the principle of a personal computer - you can change its components depending on your needs. You don't have to pay for unused channels or interfaces. Increasing base resources controller provided by simply connecting additional modules.
network cards
Removable NICs - Allows communication on a Lonworks or Ethernet network. When switching from protocol to protocol, no additional programming of the Pixel logic controller is required. Cards are ordered separately, which is undoubtedly convenient when ordering controllers.
Expansion modules
The advantages of using extension modules are undeniable.
allow you to increase the number of I / O channels up to 64. When adding new modules, there is no need to dismantle the Pixel controller or disassemble it, while maximum automation of the process has been achieved: distribution of addresses, hot pickup, etc.
Memory module
The PMM module is designed for removing archives and for loading work programs into Pixel controller. The speed of preparing controllers for work increases, since it has become possible to save and transfer control programs with its help.
Graphic display
The Pixel controller's graphical display allows you to display graphics and text in various sizes.
Software packages
Programming convenience is ensured using the unique SMConsctructor tool - a package for automatically creating programs for controllers and Pixel. SMConsctructor allows you to quickly create control programs and adapt them to a specific object. The constructor has a simple intuitive interface, and anyone familiar with ventilation systems can master it.
Buy PIXEL Controller and you can get technical advice from the Group of Companies "Automation".