PLC Development 2010gMichael Kellow
Kathleen ManuelJames Kemp
www.2010g.info
Overview
• Description• Scope• Current Progress
• Communication• Software• Hardware
• Future Plans2
PLC’s Control the World
3
PLC Industries
• Water & Waste Treatment• Electricity Generation and Distribution• Mining• Manufacturing• Pharmaceuticals• Golf Clubs
4
What makes a PLC
Programmable Logic Controller
• Simple Logic Controller• Reliable• Extendable• Versatile
5
PLC vs PC or Micro
• Less Errors in Programming• High Reliability• Compatibility with Hardware and
Instuments
6
PLC Range
16 Major PLC Manufacturers
Many Smaller Manufacturers
Not Compatible with each other
7
Scope
Research, develop and construct an industry standard PLC (programmable logic controller)
for teaching purposes.
8
Current Progress
PLC Development
Communications Protocol Software Hardware
9
Communications Protocol
Some of the factors that will help determine which type of protocol to use:
• cost• redundancy• speed• repeatability• maintainability
10
Communications Protocol
Modbus • Developed by Modicon• Standard communications protocol in industry• Widespread use of Modbus in industry mainly due to:
– Cost – Maintainability
Image taken from: www.rtaautomation.com/modbustcp11
Communications Protocol
Ethernet/IP• Developed by Rockwell Automation (Allen-Bradley)• Designed for use in process control and other automation
applications
Image taken from: ethernetgateways.com12
Current Progress Software
• Kernel Design• SLC 500 Commands• Closed Source• PID Control• Ladder Logic Interpreter
13
Ladder Logic
[ I2 AND NOT (O3) ] OR [ O3 AND NOT (I2) ] = Output 214
Programming
RS Logix 50015
Hardware
Enclosure
Processor Module
Communications Modules
Expansion and I/O Modules
Power Supply
16
Future Goals
http://www.wastechcontrols.com/images/plc.jpg17
Questions