ABB REC670 Applications Manual page 606

Section 21
Remote communication
600
MaxTransmDelay indicates maximum transmission delay. Data for maximum 40 ms
transmission delay can be buffered up. Delay times in the range of some ms are
common. If data arrive in wrong order, the oldest data is disregarded.
MaxtDiffLevel indicates the maximum time difference allowed between internal clocks
in respective line ends.
64 kbit mode specific settings
TransmCurr is used to select among the following:
• one of the two possible local currents is transmitted
• sum of the two local currents is transmitted
• channel is used as a redundant backup channel
breaker-and-a-half arrangement has two local currents, and the Current Transformer
(CT) grounding for those can differ. CT-SUM transmits the sum of the two CT groups.
CT-DIFF1 transmits CT group 1 minus CT group 2 and CT-DIFF2 transmits CT group
2 minus CT group 1.
CT-GRP1 and CT-GRP2 transmit the respective CT groups, and setting
RedundantChannel determines that the channel is used as a redundant backup channel.
The redundant channel takes the CT group setting of the main channel.
RemAinLatency corresponds to LocAinLatency set in the remote IED.
AnalogLatency specifies the time delay (number of samples) between actual sampling
and the time the sample reaches LDCM. The value is set to 2 when transmitting analog
data. When a merging unit according to IEC 61850-9-2 is used instead of the TRM,
this parameter shall be set to 5.
CompRange value indicates the current peak value over which truncation is made. To
set this value, knowledge of fault current levels is required. It is recommended to set
the minimum range that will cover the expected fault current value. For example, if a
40kA fault level is expected on the network, the 0-50kA settings range should be
chosen.
2 Mbit mode specific settings
RedundantCh is used to set the channel as a redundant backup channel. The redundant
channel takes the CT group setting of the main channel, and ignores the CT group
configured in its own transmit block.
1MRK 511 401-UUS A
Bay control REC670 2.2 ANSI
Application manual