Chapter 2.
NAMES AND FUNCTIONS OF PARTS
2  -  1 Structure
The DCP551 consists of a main unit, console, case, and terminal base.
DCP551A model DCP551B model
2-1
Console
  Provides 7-segment displays, LEDs, operation keys, 
  and a loader interface unit.
Terminal base
  Provides terminals to connect a power supply, 
  input, output, event output, external switch input, 
  and auxiliary output (optional) , etc.
Case
Main unit
  Console and electric circuit board, etc.
Terminal cover
  Covers power supply and 
  prevents electric shock.