ABB Rellon 620 Series - Link Test Interval; Diagnostics; Status; Received Frames

Section 3 1MAC306892-MB C
Vendor-specific implementation
24 RER620
Communication Protocol Manual
• Max: 255000
• Default: 15000
•Unit: ms
In case of longer data transmission in one direction only, an S format has to be sent in the
other direction to acknowledge the APDUs before buffer overflow or time out. t2 is the
time-out for acknowledges in case of no data messages. t2 < t1, resolution 1 s. The timeout
setting should be set as a multiple of 1000ms.
3.6.25 Link test interval
• Min: 1000
• Max: 172800000 (48 hours)
• Default: 20000
•Unit: ms
Unused, but open, connections may be periodically tested in both directions by sending
test APDUs (TESTFR = act) which are confirmed by the receiving station sending
TESTFR = con. Both stations may initiate the test procedure after a specified period of
time in which no data transfers occur (time out). The reception of every frame - I frame, S
frame or U frame - retriggers timer t3. The accuracy for t3 is 1 second. The timeout setting
should be set as a multiple of 1000ms.
3.7 Diagnostics
All of the counters, with the exception of the Status point, show value '-1' when no
connection is established after the protective relay restart.
3.7.1 Status
The Status value is "True" when the communication is active, that is, a client has been
connected within the last 30 seconds. Otherwise it is "False".
It is possible to reset the diagnostic counters by setting the Status value to "True".
3.7.2 Received frames
The Received frames counter shows the number of accepted frames received by the
protective relay since the last startup or a diagnostic reset.
3.7.3 Transmitted frames
The Transmitted frames counter shows the number of frames transmitted by the protective
relay since last the startup or a diagnostic reset.