ACC Automation: PLC & Industrial Control Learning
Practical Tips and Techniques
We will now look at the click PLC Modbus ASCII protocol. This communication will happen in PLC ladder logic and communicate through the serial port (RS485) to a Solo process temperature controller. Modbus ASCII will be the communication protocol. Modbus is a communication protocol used to transmit information over serial lines between electronic devices. The … Read more
We will now look at the capacitive pushbutton sensor switch and indicator. Normal pushbuttons on a panel are usually a mechanical device. They can become “sticky” when too much dirt or oil is present. Capacitive push buttons do not have moving parts to stick, so the life expectancy is increased. Disinfectant sprays can be applied … Read more
The Click PLC can communicate to a remote I/O (input and output) controller modules using the Modbus protocol for communications. The BX-MBIO provides both Modbus RTU and Modbus TCP interfaces for remote IO. Modbus RTU is a serial communication and Modbus TCP is an Ethernet communication. Modbus RTU is supported over an RS-485 serial connection. … Read more
We will now look at the Click PLC Modbus TCP remote io. The Click PLC can use remote inputs and outputs from Stride. The Stride Field I/O Modules are simple and compact. They provide an economical means to connect inputs and outputs to an Ethernet Modbus TCP communication network. Every module operates as a standalone … Read more
We will now look at logging data with time and date in the Click PLC. The Click PLC can perform indirect addressing. This means that I can ask for information to be moved to and from locations in the PLC using a pointer that will indicate the address. Stephen Covey in The 7 Habits of … Read more
Wiring 3 wire DC sensors can be confusing. I recently received a question on PNP and NPN sensors. They wanted an explanation of what a sink is and how to wire one. Confusion over the Normally Open and Normally Closed function of the sensor is also a common question. Several diagrams will show a resistor … Read more
A PID (Proportional, Integral, and Derivative) control is possible with the Click PLC. The Click Programming Software version 2.50 now includes PID. This features 8 full-featured control loops with an easy graphical user interface (GUI). PID will run on all of the Ethernet-enabled Click PLCs. We will be using this PID along with a Factory … Read more
A PID (Proportional, Integral, and Derivative) control is possible with the Click PLC. A sample program was written for this PLC by Bernie Carlton in the following thread from the Automation Direct Forum. This was based on the math/process presented by Tim Wescott on is paper titled PID without a Ph.D. We will be using … Read more
Signal conditioners are used with analog current and voltage signals. They have the ability to change your input analog signal to another output analog signal. As an example, we can have 4-20mA analog input and change it to a 0-10VDC output signal so we can wire this into our PLC. Typically signal conditioners will also … Read more
A dusk to dawn sensor usually is discrete on/off of the lighting control. If we want to vary the lights to mimic more of the sunset and rise, we would use an analog output to control the lights. I was recently asked about such a program. Every day they wanted the lights to go off … Read more