1. Copyright © 2002 Delmar Thomson Learning Chapter 9 Putting Together a Modular PLC

2. Copyright © 2002 Delmar Thomson Learning Objectives  Define rack, chassis, and baseplate and tell how or why they differ.  Select the proper type of I/O to interface a specific input signal.  Explain why power supply loading must be determined as a PLC systems is configured.

3. Copyright © 2002 Delmar Thomson Learning PLCs Come in Two Styles  The I/O of a fixed PLC is built in and not changeable.  A modular PLC consists of user- selected I/O modules, a processor, a power supply, and a chassis.

4. Copyright © 2002 Delmar Thomson Learning Rack, Chassis, or Baseplate?  Depending on the modular PLC manufacturer, the term used to identify the hardware device that holds all the modules, processor and power supply may vary.  Some use rack, chassis, or baseplate.

5. Copyright © 2002 Delmar Thomson Learning Module Installation into a Four-Slot SLC 500 Chassis Image courtesy of Allen-Bradley, a Rockwell Automation business

6. Copyright © 2002 Delmar Thomson Learning Module Installation into a Four-Slot SLC 500 Chassis (cont’d.)  The General Electric Series 90-30 incorporates the processor into the baseplate for the low end modular PLCs.  Baseplates come in five-slot and ten- slot models.

7. Copyright © 2002 Delmar Thomson Learning Series 90-30 PLC Model 331 CPU Image courtesy of GE Fanuc Automation

8. Copyright © 2002 Delmar Thomson Learning Removing a GE Series 90-30 I/O Module Image courtesy of GE Fanuc Automation

9. Copyright © 2002 Delmar Thomson Learning Local I/O Expansion  When more I/O is required than a single chassis can hold, additional chassis can be added.  Communications cable connects expansion chassis together.  No processor in expansion chassis.  Power supply required in all chassis.  Expansion cable distance limited.

10. Copyright © 2002 Delmar Thomson Learning SLC 500 3-chassis Local Expansion Image courtesy of Allen-Bradley, a Rockwell Automation business

11. Copyright © 2002 Delmar Thomson Learning Remote I/O  Remote I/O allows greater cable distance between chassis.  Typically a serial link.  SLC 500 remote I/O maximum cable length 10,000 feet.  Baud rate of 57.6 K bits per second.

12. Copyright © 2002 Delmar Thomson Learning SLC 500 Remote I/O Example Image courtesy of Allen-Bradley, a Rockwell Automation business

13. Copyright © 2002 Delmar Thomson Learning SLC 500 Remote I/O Example (cont.’d)  SLC 500 uses 1747-SN scanner in local chassis.  SN scanner communicates with remote chassis.  1747-ASB communication module required in each remote chassis.

14. Copyright © 2002 Delmar Thomson Learning SLC 500 Remote I/O Example (cont.’d)  Remote I/O allows I/O to be “distributed” around the plant floor.  PanelView operator interface terminals as well as variable frequency drives can be connected on a remote I/O link.

15. Copyright © 2002 Delmar Thomson Learning PLC Networking  A single chassis PLC can be part of a larger factory-wide communication network.  Each PLC has own processor.  Each device on the network is a node or station on the network.  Each node must have a unique identifier known as the node address.

16. Copyright © 2002 Delmar Thomson Learning Advantages to Networking  Multiple stand-alone PLCs networked together.  Share information between processors.  Share control of the process.  Operator interface devices input or display information from multiple PLC processors.  PLC control of other devices such as VFDs.

17. Copyright © 2002 Delmar Thomson Learning Current SLC 500 Network Connectivity  Remote I/O  Data Highway-485  Data Highway Plus  Control Net  Device Net  Ethernet

18. Copyright © 2002 Delmar Thomson Learning AB SLC 500 Data Highway-485 Network Image courtesy of Allen-Bradley, a Rockwell Automation business

19. Copyright © 2002 Delmar Thomson Learning Selection and Placement of I/O Modules  Consider Input and Output Signals  Modules are divided into family groups.  The appropriate input or output module is selected by determining incoming and outgoing signals.  Match I/O signals to proper module.

20. Copyright © 2002 Delmar Thomson Learning Table for Determining Input and Output Types

21. Copyright © 2002 Delmar Thomson Learning I/O Module Selection from Input and Output Type

22. Copyright © 2002 Delmar Thomson Learning Power Supply Selection  Each modular PLC chassis, rack, or baseplate must have own power supply.  Power supply designed to handle specific load.  Power supply loading is dependant on modules installed.

23. Copyright © 2002 Delmar Thomson Learning Power Supply Selection (cont’d.)  Proper power supply sizing will help avoid intermittent problems or power supply shutdown due to an overloaded power supply.

24. Copyright © 2002 Delmar Thomson Learning SLC 500 Power Supply Specifications Image courtesy of Allen-Bradley, a Rockwell Automation business

25. Copyright © 2002 Delmar Thomson Learning Determine Power Supply Loading  Proper size power supply is selected to handle load placed upon it by the I/O module mix.  Power supply loading can be manually calculated using manufacturers’ tables and module loading data.  PLC programming software can provide power supply loading calculation feature.

26. Copyright © 2002 Delmar Thomson Learning RSLogix 500 Power Supply Loading

27. Copyright © 2002 Delmar Thomson Learning Installing a SLC 500 Power Supply Image courtesy of Allen-Bradley, a Rockwell Automation business

28. Copyright © 2002 Delmar Thomson Learning Series 90-30 Power Supply Image courtesy of GE Fanuc Automation