Tag Archives: plc ladder logic examples

Productivity 1000 Series PLC Modbus ASCII Protocol

Modbus is a communication method used for transmitting information over serial lines between electronic devices. The device requesting the information is called the Modbus Master (Client) and the devices supplying information are Modbus Slaves (Servers). This protocol was originally developed by Modicon systems.
Modbus protocol comes in basically three different types. Ethernet (Modbus TCP) or Serial (Modbus RTU or Modbus ASCII). Modbus TCP and Modbus RTU come as standard protocols in the productivity series of PLCs.

We will connect the Productivity 1000 PLC to a Solo process temperature controller. This will be done using the Modbus ASCII protocol over serial RS485 communication wire. (Media) The present and set values (PV / SV) will be read from the Solo controller and the set value will be written when required. Let’s get started. Keep on Reading!

Productivity 1000 PLC to Modbus TCP RTU Remote IO Controller BX-MBIO

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 1000 PLC to Stride Field IO Modbus TCP

The Productivity Series of 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 Modbus TCP server and can be configured via a built-in web server.
Previously we looked at the Stride Field Remote IO Modules Modbus TCP Ethernet wiring and configuration.
Stride Field Remote IO Modules Modbus TCP Ethernet
Unboxing SIO MB12CDR and SIO MB04ADS Video
Powering and Configuring Video

We will be connecting two Stride remote inputs and outputs to the P1000 PLC. Modbus TCP will be the protocol over Ethernet to communicate to the SIO-MB12CDR and SIO-MB04ADS units.

SIO-MB12CDR
– STRIDE discrete combo module, Input: 8-point, 12-24 VDC, sinking, Output: 4-point, relay, (4) Form C (SPDT) relays, 2A/point, (1) Ethernet (RJ45) port(s), Modbus TCP server.
SIO-MB04ADS
– STRIDE analog input module, 4-channel, current/voltage, 16-bit, isolated, input current signal range(s) of +/- 20 mA, input voltage signal range(s) of +/- 10 VDC, (1) Ethernet (RJ45) port(s), Modbus TCP server.

We will be reading an analog voltage into the Productivity 1000 PLC from the remote IO unit. We will then set an output to pulse on and off at a time range indicated by this analog signal. The output will be on the other remote IO unit and will trigger the input to signal. We will look at the Frequency, Count, and Status of this input. Our Productivity 10000 PLC program will also take into consideration watchdog (communication time out) and power-up events for the Stride remote input and output units.
Let’s get started. Keep on Reading!

Productivity 1000 Series PLC AdvancedHMI Modbus TCP Ethernet Communication

Advanced HMI is a powerful, adaptable HMI/SCADA (Supervisory Control and Data Acquisition) development package that takes advantage of Visual Studio. There is no coding required and you can simply drag and drop items onto the page. The best thing is that the software is free. We will look at using AdvancedHMI with the Productivity 1000 Series PLC.

Our sample Productivity 1000 PLC program will display a digital panel meter and a gauge of a value in the PLC. Stop and start momentary pushbuttons on the HMI will allow this number to increase or stop. An indication will turn green when the number is increasing and red when it has stopped. The AdvancedHMI package will communicate Modbus TCP over Ethernet to the Productivity 1000 PLC. We will be able to monitor our process via the AdvancedHMI window. Let’s get started.

Continue Reading!

Productivity 1000 Series PLC Modbus RTU Serial Communication

The productivity series of PLCs comes with 4 built-in communication ports for easy connectivity to your PC or various industrial networks. Serial protocols like Modbus RTU can be utilized with either the RS232 or RS485 ports on this PLC. Modbus RTU is an open (published) protocol that uses the Master / Slave architecture. It’s a very common protocol used in industrial automation controls.

We will be using the RS485 (2-wire) port to communicate to a Solo Process Temperature Controller. Modbus RTU will be the protocol used on this serial communication media. The PLC will be the master and the Solo process temperature controller will be the slave. You will soon see how the Productivity Series of PLC’s is the best way to handle communication to other devices. Let’s get started. Continue Reading!

Productivity 1000 Series PLC Web Server

The productivity series of PLCs has a built in web server. This web server function can make a non secure (HTTP) connection to the CPU. This is done with your browser. You can then view read only system tags and open, save or delete files stored on the micro SD drive.

Previously we stored data logged files on the USB (Micro SD) storage device. We will now start and configure the web server function. Look at the files from our data logger and view the system files available. Let’s get started. Continue Reading!

Productivity 1000 Series PLC Data Logger

The productivity series of PLCs has a built in data logger. This easy data logger will log up to 64 tag values on a USB (Micro SD) storage device connected to the CPU. The logs will be stored in CSV (Comma Separated Values) file format. Logging can be triggered by the rising edge transition of a Boolean tag (event) or configured to occur at regular intervals (scheduled).

A USB storage device should be normally connected if logging data. The CPU maintains an internal 73KB buffer for temporarily logging data while no USB storage device is present. Data in the buffer will not be retained through a power cycle. Let’s get started. Continue Reading!

Productivity 1000 Series PLC Drum Sequencer Instructions

The productivity series of PLCs has a Drum and Sequencer instruction.
Drum instructions are great tools. They mimic an electromagnetically drum sequencer. Have you ever seen the mechanisms of a music box? Ok so it’s a little drum with pegs that catch and flick the chimes in a particular sequence to play whatever tune is on the drum. So in the PLC you can have a drum driven by an event, (input from a limit switch or button), or by time.

Sequencers are similar to the drum instruction. The sequencer output can have up to 16 Boolean, Integer or Numerical Tags per step. Drum instruction outputs are limited to the same 16 bit (Boolean) outputs. Each step in the sequencer can be defined by time or /and event and specified outputs can be set going into and out of the step.
We have done similar Drum instructions for the BRX Series PLC and the Click PLC.
BRX PLC Drum InstructionVideo
Click PLC Drum InstructionVideo
We will be discussing the drum and sequencer instructions in the Productivity Series PLC. Simple examples will be done to demonstrate the power of these instructions. Let’s get started. Continue Reading!

PLC Fiddle Shift Register Challenge

Shift registers will move (shift) bits in a word (register) to the left or right.

If we look at an example of boxes moving along a conveyor belt, the boxes would represent the bits in the register. The movement of the conveyor would be the shifting of the register that represents the movement of the boxes.

Shift registers are a form of sequential logic, which involves the present inputs and the prior history. All of the prior history is remembered.
We will be making a shift register in PLC Fiddle with the instructions provided. The output of the shift register will then be looked at for a reject area. Let’s get started. Continue Reading!

Productivity 1000 Series PLC Program Control

The program control method and instructions will allow us to specify what parts of the logic get solved and when this happens. This will control how the PLC will scan and solve your logic in your program using a synchronous PLC Scan. Understanding the PLC program scan will explain the synchronous and asynchronous program scanning.
Individual ladder logic programs get solved left to right, top to bottom. The result of the rung before is available for the next rung. The Task Management provides a method to clearly see the overall flow of your PLC program. Looking into the folders of the task management we can see blocks of code. These blocks of contain the ladder logic that will solve our logic. Instructions within the ladder logic code can also determine how the PLC will solve the logic.

We will be looking at using program control in the Productivity 1000 Series PLC.
Let’s get started. Continue Reading!