GE D30 Instruction Manual page 146

5.2 PRODUCT SETUP
5
Figure 5–12: DUAL-CHANNEL CLOSED LOOP (DUAL-RING) CONFIGURATION
In the above application, the following settings should be applied:
UR IED 1:
DIRECT OUTPUT DEVICE ID:
DIRECT I/O RING CONFIGURATION:
UR IED 3:
DIRECT OUTPUT DEVICE ID:
DIRECT I/O RING CONFIGURATION:
In this configuration the following delivery times are expected (at 128 kbps) if both the rings are healthy:
IED 1 to IED 2: 0.2 of power system cycle; IED 1 to IED 3: 0.2 of power system cycle;
IED 2 to IED 3: 0.2 of power system cycle
The two communications configurations could be applied to both permissive and blocking schemes. Speed, reliability and
cost should be taken into account when selecting the required architecture.
b) CRC ALARM CH1(2)
PATH: SETTINGS PRODUCT SETUP
CRC ALARM CH1
The D30 checks integrity of the incoming direct input/output messages using a 32-bit CRC. The CRC Alarm function is
available for monitoring the communication medium noise by tracking the rate of messages failing the CRC check. The
monitoring function counts all incoming messages, including messages that failed the CRC check. A separate counter adds
up messages that failed the CRC check. When the failed CRC counter reaches the user-defined level specified by the
ALARM CH1 THRESHOLD
FlexLogic™ operand is set.
When the total message counter reaches the user-defined maximum specified by the
ting, both the counters reset and the monitoring process is restarted.
The operand shall be configured to drive an output contact, user-programmable LED, or selected communication-based
output. Latching and acknowledging conditions - if required - should be programmed accordingly.
The CRC Alarm function is available on a per-channel basis. The total number of direct input/output messages that failed
the CRC check is available as the
value.
• Message Count and Length of the Monitoring Window: To monitor communications integrity, the relay sends 1
message per second (at 64 kbps) or 2 messages per second (128 kbps) even if there is no change in the direct out-
puts. For example, setting the
minutes at 64 kbps and 80 minutes at 128 kbps. If the messages are sent faster as a result of direct outputs activity, the
5-48
TX2 TX1
UR IED 1
RX1 RX2
TX1
RX2
"1"
"Yes"
"3"
"Yes"
DIRECT I/O
CRC ALARM CH1
FUNCTION: Disabled
CRC ALARM CH1
MESSAGE
MESSAGE COUNT: 600
CRC ALARM CH1
MESSAGE
THRESHOLD: 10
CRC ALARM CH1
MESSAGE
EVENTS: Disabled
setting within the user-defined message count
ACTUAL VALUES
CRC ALARM CH1 MESSAGE COUNT
D30 Line Distance Relay
RX1
UR IED 2
TX2
RX1
UR IED 3
TX2
UR IED 2:
DIRECT OUTPUT DEVICE ID:
DIRECT I/O RING CONFIGURATION:
CRC ALARM CH1(2)
Range: Enabled, Disabled
Range: 100 to 10000 in steps of 1
Range: 1 to 1000 in steps of 1
Range: Enabled, Disabled
CRC ALARM 1 CH1 COUNT
STATUS DIRECT INPUTS
to "10000", corresponds a time window of about 160
5 SETTINGS
RX2
TX1
842715A1.CDR
"2"
"Yes"
, the
DIR IO CH1 CRC ALARM
CRC ALARM CH1 MESSAGE COUNT
CRC FAIL COUNT CH1(2)
GE Multilin
CRC
set-
actual