Conveyor Belt Production Line ENG311 Project 1 Group Members: Nicholas Ross Lane, Radomir Sebesta, Tully Woodland

Project Overview: Introduction Background Project Objectives Safety Functions Hardware Program Logic & Subroutines PLC Configuration Wiring Diagram Summary and Further Development Demonstration

Introduction: Implement the Moeller Easy 719-DC-RC Programmable Logic Controller to control a conveyor production line model 226006 from Staudinger, that meets the project objectives. The Moeller Easy controller is an industrial computer which makes use of Ladder Logic Programming. Ladder Logic programming language works by scanning the states of inputs and memory bits sequentially in a vertical fashion.

Background: The conveyor belt production line has been designed to detect material in the feed shoot and push it onto the conveyor belt. The material is then drilled and afterwards, the final product is moved along the conveyor to the dispatch position, where it can be removed either by hand or by fork truck. The conveyor belt makes use of several safety functions outlined in the next section to prevent any harm to personnel or damage to equipment.

Background: (Continued) The Moeller Easy 719-DC-RC hardware consists of the following: 8 digital and 4 analogue input terminals, 6 digital output terminals, and LCD display with keypad. Applications of this controller are: Lighting management, Heating, ventilation and cooling (HVAC), small machinery control, and irrigations systems. The conveyor belt consists of a total of five sensors which coincide with the two ram positions and the three product positions. Also utilised are three motors; motor one uses a forward and reverse polarity to operate the ram, motor two operates the drill, and motor three operates the conveyor.

Project Objectives: The emergency stop button should physically remove power to all actuators as well as disable them in the PLC. The laser sensor switch will disable actuators in PLC only. The conveyor is to auto power off any moving parts if the conveyor is unmanned and there is no material along the production line. The ram is to press the material onto the conveyor when there is product in the feed and the conditions are safe to do so.

Project Objectives: (Continued) The drill press should drill into the centre of the block for 3 seconds, the conveyor is to be idol during this operation. Conveyor belt is to stop when there is product at the dispatch area, and is to not activate until the material is removed for at least 1.5 seconds. We started by identifying what hardware would be required and then assessing how to utilise the inputs and outputs on the PLC.

Safety Functions: Emergency stop button – The Emergency stop is to be used in the event that machinery could cause harm to personnel or there is equipment malfunction. Laser Sensor Switch – A laser sensor switch has been implemented to ensure employees keep a safe distance from the moving parts of the process. Auto conveyor off – Prevents conveyor running unmanned when there is no material in the feed stack or the drill the conveyor belt will auto shut off after 3 seconds.

Safety Functions: (Continued) Dispatch area – Prevents personnel from coming in contact with moving parts along the conveyor when removing product. Debugging – Auto / Manual mode is used to troubleshoot the conveyor belt if it enters a fault condition, only available to technicians. Best Practice – Before changes are made to the program it is considered best practice to upload the program to the PC.

Hardware

Drill (Q4) Conveyor (Q1) End Positon (I5) Ram In (I3) Ram Out (I2) Drill Position (I4) Feed (I1) Ram in (Q2) Ram out (Q3)

Supply (+24V) Digital Inputs I1 –I12 Touch Pad LCD screen Coms Port Digital Outputs (Q1 – Q6)

Blocks Diodes Reed Switch (5 of) Fuses DC Motors Emergency Stop Finder Relay (4 of) Switches Lights

Program Logic

Subroutine - Manual

Subroutine – Drill, Ram In, Ram Out

Subroutine – Conveyor, Off Conveyor, Shutdown

Subroutine – Initialise, Forklift Delay

PLC Configuration: Input Number Tag Name Function I01 “Block In Feed” I01 is high if there is a block in the feed. I02 “Ram Out Position” I02 is high if the ram is fully extended outwards I03 “Ram In Position” I03 is high if the ram is extended inwards I04 “Drill Position” I04 is high when there is a block under the drill press I05 “End Position” I05 is high when there is a block in the end bay I06 “Stop” I06 is high when one of the stops switches has been triggered. I07 “Start” I07 is high when the start button is pressed

PLC Configuration: (Continued) Output Number Tag Name Function Q01 “Conveyor” Activates conveyor motor Q02 “Ram In” Activates ram motor forwards Q03 “Ram Out” Activates ram motor backwards Q04 “Drill On” Activates drill motor Q05 “On Light” Activates “On” light Q06 “Off Light” Activates “Off” light

Wiring Diagram

Summary: This project stressed the importance of functional safety on industrial machinery like conveyor belt systems. A typical conveyor belt should have a start, and stop button to operate the process. Emergency stop buttons are used to stop all machinery in the case of an emergency only. Other safety features are typically added to conveyors, which have been implemented into this project (laser sensor switch).

Problems Encountered: The greatest obstacle of this project has been group communication with regards to the ram position. Overcome by implementing a written I/O allocation list. The second obstacle has been implementing the Auto/Manual mode into the program with the limited physical outputs. This was overcome with hard wiring changes along with a jump in the ladder logic. The ram in position reed switch was not activating properly, this occurred when the ram position would initialise. Overcome by implementing an on delay timer to reset the ram in the code. During early implementation our seemingly working code enabled a situation whereby if the ram was stopped inbetween both sensors it could not start again. This was overcome by creating an initialising phase each time the program starts.

Further Development: We could have added a analogue comparator to utilise the analogue inputs however this is not practical for the application. Use of the motion detector as an additional safety feature, this will have a similar function to the laser sensor switch. Implementation an encoder to track the position of the product along the conveyor belt production line.

References: Moeller Easy 719-DC-RC Manual - Accessed 25/03/2017 http://www.jpn-moeller.co.jp/easy/img/h1508g.pdf