Typical RTU Hardware that mau be encountered
are
- Control processor and associated memory
 
- Analog inputs
 
- Analog outputs
 
- Counter inputs
 
- Digital inputs
 
- Digital outputs
 
- Communication interface(s)
 
- Power supply
 
- RTU rack and enclosure
 
Requirements for RTU system:
Hardware:
Individual RTU expandability (typically up to 200 analog and
digital points)
- Off the shelf modules
 
- Maximum number of RTU sites in a system shall be expandable to
255
 
- Modular system – no particular order or position in
installation (of modules in a rack)
 
- Robust operation – failure of one module will not affect the
performance of other modules
 
- Minimization of power consumption (CMOS can be an
advantage)
 
- Heat generation minimized
 
- Rugged and of robust physical construction
 
- Maximization of noise immunity (due to harsh environment)
 
- Temperature of –10 to 65°C (operational
conditions)
 
- Relative humidity up to 90%
 
- Clear indication of diagnostics
 
- Visible status LEDs
 
- Local fault diagnosis possible
 
- Remote fault diagnostics option
 
- Status of each I/O module and channel (program
running/failed/communications OK/failed)
 
- Modules all connected to one common bus
 
- Physical interconnection of modules to the bus shall be robust
and suitable for use in harsh environments
 
- Ease of installation of field wiring
 
- Ease of module replacement
 
- Removable screw terminals for disconnection and reconnection of
wiring