Areva MiCOM P441 - Page 89

Update Documentation P44x/EN AD/E44
MiCOM P441, P442 & P444 Page 71/82
9.10.2.7 Modem Connection
For long distance communication, modems may be used in which the case the following
connections should be made.
Px40 Relay with
InterMiCOM
1
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
8
9
Px40 Relay with
InterMiCOM
DCD
RxD
TxD
DTR
GND
RTS
DCD
RxD
TxD
DTR
GND
RTS
-
-
-
-
-
-
-
-
-
-
-
-
P1341ENa
DCD
RxD
TxD
GND
DCD
RxD
TxD
GND
Communication
Network
INTERMiCOM TELEPROTECTION VIA A MODEM LINK
This type of connection should also be used when connecting to multiplexers which have the
ability to control the DCD line.
With this type of connection it should be noted that the maximum distance between the Px40
relay and the modem should be 15m, and that a baud rate suitable for the communications
path used should be selected.
9.10.3 Functional Assignment
Even though settings are made on the relay to control the mode of the intertrip signals, it is
necessary to assign interMiCOM input and output signals in the relay Programmable
Scheme Logic (PSL) if InterMiCOM is to be successfully implemented. Two icons are
provided on the PSL editor of MiCOM S1 for “Integral tripping In” and “Integral tripping out”
which can be used to assign the 8 intertripping commands. The example shown below in
figure 2 shows a “Control Input_1” connected to the “Intertrip O/P1” signal which would then
be transmitted to the remote end. At the remote end, the “Intertrip I/P1” signal could then be
assigned within the PSL. In this example, we can see that when intertrip signal 1 is received
from the remote relay, the local end relay would operate an output contact, R1.
EXAMPLE ASSIGNMENT OF SIGNALS WITHIN THE PSL
It should be noted that when an InterMiCOM signal is sent from the local relay, only the
remote end relay will react to this command. The local end relay will only react to
InterMiCOM commands initiated at the remote end.