Eia(Rs)232 Configuration; Eia(Rs)232 Intermicom Communications; Intermicom Loopback Testing & Diagnostics - GE P741 Technical Manual

Commissioning
MiCOM P741, P742, P743
Check that communications can be established with this relay using the portable PC.
4.2.8.3

EIA(RS)232 configuration

Connect a portable PC running the appropriate software (e.g. S1) to the rear EIA(RS)2321
port of the relay.
The second rear communications port connects via the 9-way female D-type connector
(SK4). The connection is compliant to EIA(RS)574.
Connections to the second rear port configured for EIA(RS)232 operation can be made using
a screened multi-core communication cable up to 15m long, or a total capacitance of
2500pF. The cable should be terminated at the relay end with a 9-way, metal shelled, D-type
male plug.
Ensure that the communications baud rate and parity settings in the application software are
set the same
[0E90:COMMUNICATIONS, RP2 Address] must be set to a value between 1 and 254. The
second rear communications port configuration [0E88: COMMUNICATIONS RP2 Port
Config.] must be set to EIA(RS)232.
Check that communications can be established with this relay using the portable PC.
4.2.8.4

EIA(RS)232 InterMiCOM communications

4.2.8.5 InterMiCOM loopback testing & diagnostics
The "Loopback" test facilities, located within the [15 INTERMICOM COMMS] column of the
relay menu, provide a user with the ability to check the software and hardware of the
InterMiCOM signaling. If 'INTERMICOM COMMS' column is not visible, check that [0490
InterMiCOM] is enabled in the [09 CONFIGURATION] column.
Note that by selecting the [1550 Loopback Mode] to "Internal", only the internal software of
the relay is checked whereas "External" will check both the software and hardware used by
InterMiCOM. When relay is switched into either 'Loopback Mode' the relay will automatically
use generic addresses and will inhibit the InterMiCOM messages to the PSL by setting all
eight InterMiCOM message states to zero.
Set 'External' and connect the transmit and receive pins together (pins 2 and 3) and ensure
that the DCD signal is held high (connect pin 1 and pin 4 together) as per Figure 4 below.
The loopback mode will be indicated on the relay frontplate by the amber Alarm LED being
illuminated and a LCD alarm message, "IM Loopback".
FIGURE 4: CONNECTIONS FOR EXTERNAL LOOPBACK MODE
as those in the relay.
P74x/EN CM/Na7
The relays courier address
(CM) 10-17
in cell
CM