Communications; Remote Communications; Self Checks And Error Routines - GE MLP1000 Manual

5 COMMUNICATIONS

5.1 REMOTE COMMUNICATIONS

The user can communicate with the MLP in two modes:
- Local: Communications are accomplished through the keyboard and monitor
situated on the front panel of the relay.
- Remote: Communications are accomplished through the serial port located on the
rear panel of the relay.
The MLP is provided with a half duplex serial communications module which permits
it's utilization as part of a completely integrated substation protection and control system.
You can connect and remotely control up to 255 MLP systems with a CPR
communications concentrator unit, which through the use of a modem can be connected to
a PC compatible computer. The MLP is connected via a 20 mA current loop, fiber optics, or
an RS232 cable (see figure 1).
MLP
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The MLP uses serial communications only for interfacing with external units in such
a way that you can only set and request data in this mode. Needless to say, if for any
reason communications are cut, the MLP continues protecting the fine and stores data in
it's memory for transmission once communications have been reestablished.
The protection functions remain active during communications. While changing the
settings in local mode, the MLP continues protecting the system with the previous settings
until the user has finished making the changes. In this instant, an almost instantaneous
change of the settings is performed.

5.2 SELF CHECKS AND ERROR ROUTINES

When the MLP detects a critical error in one of it's components, whether during
initialization or in use, it will immediately enter into a reinitialization cycle attempting to solve
the problem. The error message "HW ERROR" will appear on the screen.
GEK-98846A
PC
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