Previously we created our first program using the Productivity Suite Software and transferred this to our connected Productivity 2000 Series PLC. One of the most important aspects of programming the PLC is to document. This will aid you and your team in programming, troubleshooting, and modifying the automation control system. Your documentation should read like a book so information can be quickly obtained when required. Time spent on the PLC documentation will be priceless when you go to read your program in 1, 3, or 10 years from now. The Productivity Suite software provides several different methods for documenting your PLC program.
Tag Names and Details, Task Names and Descriptions, Rung Comments and Instruction comments are the ways that we will be looking at documenting our PLC program. Let’s get started. Keep on Reading!
The Machine Simulator (MS) is part of the EasyPLC software suite. It has many built-in machines that can be programmed. The chain conveyor is one of these machines. It will transfer large and small boxes on the line to different locations. The productivity series of PLCs will be used to program this virtual machine.
Using the Productivity Suite software, we will connect the simulator to the chain conveyor transfer machine. This will be done using Modbus TCP (Ethernet) for communications. Using the five steps for program development we will show how this is programmed. Let’s get started. Keep on Reading!
You can add a remote PLC slave rack of productivity 1000 series modules using a P1-RX. Up to 4 remote I/O base controllers can be added to the P1000 system.
We will be updating our P1-540 CPU unit to a P1-550 CPU in order to take advantage of remote IO. A P1-RX remote IO-based controller will be added and configured. Let’s get started. Keep on Reading!
We will now look at the productivity 1000 plc modbus tcp rtu communication to the BX-MBIO controller.
The Productivity 1000 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. Modbus RTU is a serial communication and Modbus TCP is an Ethernet communication. Modbus RTU is supported over an RS-485 serial connection. Modbus TCP is supported over an Ethernet connection. They function as listening/replying devices (slave, server) and can connect with any mastering (master, client) device that communicates using the Modbus protocol.
Previously we looked at the BX-MBIO Modbus RTU TCP Remote IO Controller wiring and configuration.
Modbus RTU TCP Remote IO Controller BX-MBIO
– BX-MBIO Hardware Video
– BX-MBIO Powering and Configuring Video
We will connect the Productivity 1000 PLC to the Modbus remote IO. This will be done using the Modbus TCP and Modbus RTU protocol. Ethernet and serial RS485 communication to the BX-MBIO unit will be the media.
The BX-MBIO remote I/O expansion units feature the following:
• RJ45 Ethernet port for communications via Modbus TCP
• RS485 serial port for communications via Modbus RTU
• Supports up to 8 additional Expansion Modules (Add the discrete or analog I/O you require)
• AC and DC powered units available
• AC powered units include an integral 24VDC auxiliary output power supply
• Power connector and serial port connector included
Let’s get started. Keep on Reading!
Productivity PLC – PID Ramp Soak Instruction
The purpose of a ramp soak instruction is to make gradual, controlled changes in temperature (Ramp), followed by a temperature hold (Soak) period.
We will be using our Proportional-Integral-Derivative PID Instruction that we looked at last time to apply the ramp/soak instruction.
Using the immersion heater in a cup of water to keep the temperature at a constant value, we will be adjusting the profile of the temperature as we increase the set point (Ramp) and hold that set point for a predetermined time. (Soak)
We will be modifying our existing program from our PID loop instruction. Let’s get started. Continue Reading!
PID Loop (PID) Instruction (Auto Tuning) – Productivity 1000 PLC
A Proportional-Integral-Derivative algorithm is a generic Control Loop feedback formula widely used in industrial control systems. A PID algorithm attempts to correct the Error between a measured process variable and the desired setpoint by calculating and then outputting a corrective action that can adjust the process accordingly and rapidly, to keep the Error to a minimum.
The following links will explain the PID instruction.
We will be using an immersion heater in a cup of water to keep the temperature at a constant value. Using the Productivity Suite software we will perform an autotune on our PID instruction.
Our immersion heater will be controlled through a relay using time proportional control from our PID output. Let’s get started. Continue Reading!