CO cycle
Close-open cycle
Codirectional
Way of transmitting G.703 over a balanced line. Involves two twisted
pairs making it possible to transmit information in both directions
COM
Command
COMTRADE
Standard Common Format for Transient Data Exchange format for
Disturbance recorder according to IEEE/ANSI C37.111, 1999 / IEC
60255-24
Contra-directional
Way of transmitting G.703 over a balanced line. Involves four twisted
pairs, two of which are used for transmitting data in both directions
and two for transmitting clock signals
COT
Cause of transmission
CPU
Central processing unit
CR
Carrier receive
CRC
Cyclic redundancy check
CROB
Control relay output block
CS
Carrier send
CT
Current transformer
CU
Communication unit
CVT or CCVT
Capacitive voltage transformer
DAR
Delayed autoreclosing
DARPA
Defense Advanced Research Projects Agency (The US developer of the
TCP/IP protocol etc.)
DBDL
Dead bus dead line
DBLL
Dead bus live line
DC
Direct current
DFC
Data flow control
DFT
Discrete Fourier transform
DHCP
Dynamic Host Configuration Protocol
DIP-switch
Small switch mounted on a printed circuit board
DI
Digital input
DLLB
Dead line live bus
DNP
Distributed Network Protocol as per IEEE Std 1815-2012
DR
Disturbance recorder
DRAM
Dynamic random access memory
DRH
Disturbance report handler
DSP
Digital signal processor
DTT
Direct transfer trip scheme
ECT
Ethernet configuration tool
EHV network
Extra high voltage network
EIA
Electronic Industries Association
EMC
Electromagnetic compatibility
EMF
Electromotive force
Section 10
1MRK 500 127-UEN D
Glossary
86
670 series
Operation manual