TILI Automation

 In this article, we will learn about the types of CPU communication port available on the Siemens PLC. Communication is an essential part of any control system. Without communication field devices, network switches, HMI, PLC can’t talk to each other. CPU Communication Ports In the Siemens PLC, we have several types of ports are available to communicate with other devices. Let’s dig deeper to understand each type of communication port. MPI (Multi-Point Interface) MPI port is used  RS-485  communication protocol. We use the MPI port when we have to transfer an existing program to the PLC. We can achieve it by connecting it with a PC adapter. You can connect CPU with an HMI; this way data can easily transfer to the HMI. You can also connect with another automation facility. DP (Decentralized Peripheral) Another communication port looks the same as MPI as this also used RS-485 communication protocol. DP port provides an even higher data transfer rate than an MPI port. You ca...

 OpenPLC is an open-source Programmable Logic Controller that is based on an easy to use the software. The OpenPLC project was created in accordance with the IEC 61131-3 standard, which defines the basic software architecture and programming languages for PLCs. OpenPLC is mainly used on industrial and home automation, the internet of things, and SCADA research. You can check OpenPLC in action on the short video below. OpenPLC Editor is a software that lets you write  PLC programs  for the OpenPLC runtime. The programs are written according to the IEC 61131-3 standard. The editor is very simple to use and supports all five languages defined in the standard: Ladder Logic (LD), Function Block Diagram (FBD), Instruction List (IL), Structured Text (ST), and Sequential Function Chart (SFC). Download Open PLC ScadaBR is an open-source Supervisory Control and Data Acquisition (SCADA) system that allows you to create interactive screens, also called the Human Machine Interface ( H...

  Write a plc program where there are boxes running by start-stop pushbuttons (PB) and there is a photocell sensor to count the number of boxes and there is a set pushbutton (PB) whenever it’s pressed the counter start  counting  from a preset value. Note  the best practice to learn the PLC programming is to start writing the  PLC program , take your time before you review the answer.  Inputs & outputs: I0.0: Start Push Button (Normally Open contact) I0.1: Stop Push Button (Normally Closed Contact) I0.1: Set Push Button (Normally Open Contact) Q0.0: conveyor C1: Counter Start the Counting from a Preset Value in PLC PLC Logic Explanation Network 01 When the Start PB has pressed the set coil of the SR flip flop is energized and the  conveyor  will run. If the stop PB is pressed the reset coil of the SR flip flop is energized and the conveyor will stop. Network 02 When the carton box passes by the photocell the count up coil of the counter C01 is...

 As known about the S counters that the max allowed number to count is 999.  Write a PLC program to count more than 999 counts for one counter. Note: the best practice to learn the PLC programming is to start writing the PLC program, take your time before you review the answer.  Inputs & outputs I0.0: count up I0.1: preset value PLC Count values higher than 999 Network 01  There is a counter C0 and there is a count up contact I0.0, whenever a positive edge detected from the count up bit the counter value MW0 is increased by one. A preset value is loaded the PV of the counter to ease the simulation process, where when the preset contact I0.1 is pressed for one time the counter value is loaded by 997. Whenever the counter reaches 999 counts 2 things happen. The reset memory bit M10.0 is energized and resets the counter to zero. Then a value of 1 is added to the MW2 so that to count the number of each time the counter reaches the maximum counts 999. Network 02 ...

 Write a PLC program where you can’t change the motor direction unless the stop push button is pressed first. For instance, If the clockwise (CW) push button (PB) is pressed the motor runs in CW and if the counter-clockwise (CCW) push button is pressed the motor does not change its direction unless the stop push button is pressed first. Note: the best practice to learn the PLC programming is to start writing the PLC program, take your time before you review the answer. Inputs and Outputs: I0.0: CW Push Button (Normally Open contact) I0.1: CCW Push Button (Normally Open Contact) I0.2: Stop Push Button (Normally Closed contact) Q0.0: Motor CW Q0.1: Motor CCW Motor Stop Interlock for Changing the Direction PLC Program description Network 1: When the CW PB is pressed and the Motor CCW is not running the set bit in the flip flop is energized. When the stop PB is pressed the reset bit in the flip flop is energized. If the CW PB is pressed while the Motor CCW is running the set bit would ...

 This current to measurement conversion tool will convert an electrical signal within the range of 4 to 20 milliamps to the ideal reading of any linear measurement type and create an incremental milliamp conversion scale for each measurement range entered. Formula This tool uses the following formula to calculate the the measurement reading output from a current signal input over a 4-20mA range: Measurement Rdg = Low Limit + (High Limit – Low Limit) x (mA out -4) / 16 Parameters Current Loop Signal (4-20mA) Reading Add the current loop signal reading in milliamps (mA) between 4 and 20 mA that you want to convert. Measurement Unit Enter the measurement unit associated with the output values. Lowest Measurement Add the minimum possible value for the measurement range of your instrument. For example zero would be a typical value for most instrumentation but you can also add negative (-) or positive (+) values as well. A value in any engineering units can be used as long as it relates ...

  A timer is a PLC instruction measuring the amount of time elapsed following an event. Timer instructions come in two basic types: on-delay timers and off-delay timers. Both “on-delay” and “off-delay” timer instructions have single inputs triggering the timed function. An “on-delay” timer activates an output only when the input has been active for a minimum amount of time. PLC Timer Instructions Take for instance this  PLC program , designed to sound an audio alarm siren prior to starting a conveyor belt. To start the conveyor belt motor, the operator must press and hold the “Start” push-button for 10 seconds, during which time the siren sounds, warning people to clear away from the conveyor belt that is about to start. Only after this 10-second start delay does the motor actually start (and latch “on”): Similar to an  “up” counter , the on-delay timer’s elapsed time (ET) value increments once per second until the preset time (PT) is reached, at which time its output (Q)...