Relay Control - Only on/off control can be performed. - The frequency of failure or breakdown is high and maintenance is not easy. - Circuits are modified by changing wiring. - For large-scale systems, large space and long design period are required. - Identifying the cause of a failure or an error and replacing the failed device are not easy. Sequence Control - On/off control and complex control can be performed. - Reliability is high and maintenance is easy. - Circuits are flexibly modified by using programs. - Even for large-scale systems, large space and long design period are not required, offering flexibility and extendibility. - All failures and errors can be monitored. The failed device can be replaced easily. Reference : Mitsubishi's FA E-Learning
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Mitsubishi FX3U PLC has the analog output of voltage (0-10V) or current (4-20mA). It features a 12-bit resolution (0 to 4095). That 12-bit resolution means that this digital value is converted by the analog output module into a physical voltage or current signal based on the configuration. The PLC converts digital data with 12-bit resolution into physical voltage through a process called Digital to Analog Conversion. In short form, it is called DAC. In this case, the Register contact AI/AO (M8011) is used as a trigger to activate the WR3A instruction. WR3A uses to write the data to an analog output channel on an FX3U analog module. It is used to write analog values to an analog output channel connected to the FX3U PLC. Reference : Instrumentationtools
The MOV instruction is also used to save the hexadecimal representation of the Baud Rate, Data Bits, Parity, Stop Bit, and Comm. Protocol parameters in the D8120 register, which is stored in Hexadecimal Number. The binary format 0100 0000 1000 0001 is equivalent to the Hexadecimal number , where each bit denotes a distinct communication configuration. So, how do we use it? For example, let's assume that our desired communication setting is : Data Length : 7 bit Parity : None Stop Bit : 1 bit Baud Rate : 9600 bps Comm. Protocol : Modbus Slave Slave ID : 1 Therefore, Our Binary Code will be 0100 0000 1000 0001. Remember! This Binary Code B0 to B15 is from Least Significant Bit to Most Significa...
A PLC's datasheet contains a wealth of information that covers nearly every feature the PLC is capable of offering. The technical specifications of the PLC, such as the supply voltage, input and output types, and power rating of these IO points, will be your main concern if you are the installation engineer. The historical data may not be as important to you if you are only a PLC programmer. Instead, you will concentrate on information about the PLC memory, the amount of IO available, and the ability to add new modules. The following details in the PLC data sheet must be examined, depending on the different manufacturers: - PLC Memory - Current and Voltage Rating - Addressing Various Blocks and Data Areas - Specifications for Inputs and Outputs - Interfaces and Protocols for Communication - The Ambient Situation Different PLCs will have different features and capabilities, hence different information will be displayed on different PLC data sheets. Depending on whether you ar...
Safety PLC means Safety Programmable Logic Controller. Their functions are similar with traditional PLC. But the different is that it has additional built in features that set them apart. They are built with redundancy to prevent the failure in the system. While standard and safety PLCs have similar appearances and functions, safety PLCs include additional redundancy and safety-specific capabilities, which are typically denoted by a bright color (yellow or red). The image was provided by Rockwell Automation. Not all control systems are impossible to avoid malfunction and device failure, so it is very important in some large processes or systems. Security In the event of a failure, PLCs' predicted failure modes lessen the degree of system disturbance. It is possible to reduce wiring complexity, time, labor expenses, and wire cabinet area by substituting safety PLCs for safety relays. A safety PLC also makes future system improvements simpler and less costly because, i...
In the previous post, I wrote PLC program about Mixing and Heating process. Today, I'm going to write about Filling and Heating process in tank. It sounds like the same topic in previous post. Actually, it is different. We'll see the sequences and processes. Here is the given sequences according to the Author : 1. Fill the tank up to 80%. When the tank is filled, turn ON the heater to raise the temperature up to 70 deg. 2. When this temperature is reached, turn OFF the heater & open the outlet valve. 3. When the level in the tank falls below 10%, close the output valve. In this situation, I do the ladder diagram via Sysmac Studio which is the product of Omron. I just remind you again, most of the control processes are used with Mitsubishi, Siemen and sometimes Delta's PLC due to cost effectively. I'm going to show you how it works with Sysmac Studio. In this case, I'm only using Name Tags. Before I'm talking about ladder diagram, I would like to tell about ...