In the case of EIA(RS)232 and EIA(RS)485 the next cell selects the communication mode.
RP2 Comms Mode
IEC60870 FT1.2
The choice is either IEC60870 FT1.2 for normal operation with 11-bit modems, or 10-bit no parity.
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The next cell down controls the comms port address.
RP2 Address
255
Since up to 32 relays can be connected to one K-bus spur, as indicated in figure 10, it is necessary for each relay to have a unique address so that messages from the master control station are accepted by one relay only. Courier uses a integer number between 0 and 254 for the relay address which is set with this cell. It is important that no two relays have the same Courier address. The Courier address is then use by the master station to communicate with the relay.
The next cell down controls how long the relay will wait without receiving any massages on the rear port before it reverts to its default state, including revoking any password access that was enabled. For the rear port this can be set between 1 and 30 minutes.
In the case of EIA(RS)232 and EIA(RS)485 the next cell down controls the baud rate. For K-Bus the baud rate is fixed at 64kbit/second between the relay and the KITZ interface at the end of the relay spur.
RP2 Baud Rate
19200
Courier communications is asynchronous. Three baud rates are supported by the relay,
‘9600 bits/s’, ‘19200 bits/s’ and ‘38400 bits/s’.
3.10 InterMiCOM Teleprotection (since C2.X)
InterMiCOM is a protection signalling system that is an optional feature of MiCOM Px40 relays and provides a cost-effective alternative to discrete carrier equipment. InterMiCOM sends eight signals between the two relays in the scheme, with each signal having a selectable operation mode to provide an optimal combination of speed, security and dependability in accordance with the application. Once the information is received, it may be assigned in the Programmable Scheme Logic to any function as specified by the user’s application.
3.10.1 Physical Connections
InterMiCOM on the Px40 relays is implemented using a 9-pin ‘D’ type female connector (labelled SK5) located at the bottom of the 2nd Rear communication board. This connector on the Px40 relay is wired in DTE (Data Terminating Equipment) mode, as indicated below:
Pin Acronym InterMiCOM Usage
1 DCD “Data Carrier Detect” is only used when connecting to modems otherwise this should be tied high by connecting to terminal 4.
2 RxD “Receive Data”
3 TxD “Transmit Data”
4 DTR “Data Terminal Ready” is permanently tied high by the hardware since InterMiCOM requires a permanently open communication channel.
5 GND “Signal Ground”
6 Not used -
7 RTS “Ready To Send” is permanently tied high by the hardware since InterMiCOM requires a permanently open communication channel.
8 Not used -
9 Not used -
Depending upon whether a direct or modem connection between the two relays in the scheme is being used, the required pin connections are described below.
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3.10.2 Direct Connection
The EIA(RS)232 protocol only allows for short transmission distances due to the signalling levels used and therefore the connection shown below is limited to less than 15m. However, this may be extended by introducing suitable EIA(RS)232 to fibre optic convertors, such as the AREVA T&D CILI203. Depending upon the type of convertor and fibre used, direct communication over a few kilometres can easily be achieved.
This type of connection should also be used when connecting to multiplexers which have no ability to control the DCD line.
3.10.3 Modem Connection
For long distance communication, modems may be used in which the case the following connections should be made.
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. See P443/EN AP for setting guidelines.
3.10.4 Settings
The settings necessary for the implementation of InterMiCOM are contained within two columns of the relay menu structure. The first column entitled “INTERMICOM COMMS”
contains all the information to configure the communication channel and also contains the channel statistics and diagnostic facilities. The second column entitled “INTERMICOM CONF” selects the format of each signal and its fallback operation mode. The following table shows the relay menu for the communication channel including the available setting ranges and factory defaults.
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Setting Range Menu Text Default Setting
Min Max Step Size
INTERMICOM COMMS
IM Output Status 00000000 IM Input Status 00000000
Source Address 1 1 10 1
Receive Address 2 1 10 1
Baud Rate 9600 600 / 1200 / 2400 / 4800 / 9600 / 19200
Remote Device Px40 Px30 / Px40
Ch Statistics Invisible Invisible / Visible
Reset Statistics No No / Yes
Ch Diagnostics Invisible Invisible / Visible
Loopback Mode Disabled Disabled / Internal / External
Test pattern 11111111 00000000 11111111 -
3.11 Ethernet Rear Port (option) – since version C2.X
If UCA2.0 is chosen when the relay is ordered, the relay is fitted with an Ethernet interface card.
See P44x/EN UC/E44 section 4.4 for more detail of the Ethernet hardware.
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