20-10-2012, 06:02 PM
CCTV Network
CCTV.pptx (Size: 291.15 KB / Downloads: 28)
Control and instrumentation cables
Instrumentation cables
Carry signals from instruments to control centre
Carry low currents/voltage (4-20mA or 0-10V)
EMI has to be avoided
signal cables will be twisted pair with individual and/or overall sheath
Control cables
Carry the control voltage
High voltage (240-400V AC or 24V DC)
Generally core constructed
Communication Cables
Used for communication of third party devices with DCS\PLC
Single mode fiber optic cables
Multi mode fiber optic cables
Twisted coaxial cables
Communication Protocols
system of digital message formats and rules for exchanging messages in or between computing systems
Protocols may include signaling, authentication and error detection and correction capabilities
protocol definition defines the syntax, semantics, and synchronization of communication
Can be hardware or software