MM30-W
Doc. N° MO-0117-ING
Rev.
1
Pag.
9
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29
Copyright - 2010 - Microener
The user programmable relays (all but R5, DIAG) are normally deenergized, i.e. energized on trip.
These relays pick-up as soon as the tripping cause appears (relays controlled by the instantaneous
functions) or at the end of the set trip time delay (relays controlled by time delayed functions).
The reset after trip takes place automatically as soon as the relevant tripping cause has been cleared.
The relays R5, R DIAG are not user programmable; they are normally energized and get deenergized
on :
- internal fault of MM30-W
- Internal fault of REX-8
R5
- MM30-W power supply failure
R DIAG
- REX-8 power supply failure
- during the programming
- Interruption/fault on the serial
control communication
6. SERIAL COMMUNICATION
The relays fitted with the serial communication option can be connected via a cable bus a fiber optic bus
for interfacing with a Personal Computer (type IBM or compatible).
All the functionalities that can be operated locally (for example reading of input measurement and
changing of relay’s settings) are also possible via the serial communication interface.
Furthermore the serial port allows the user to download event recording and stored data.
The unit has a RS232 / RS485 interface and can be connected either directly to a P.C. via a dedicated
cable or to a RS485 serial bus, allowing many relays to exchange data with a single master P.C. using
the same physical serial line. A RS485/232 converter is available on request.
The communication protocol is MODBUS RTU (only functions 3, 4 and 16 are implemented).
Each relay is identified by its programmable address code (NodeAd) and can be called from the P.C.
A dedicated communication software (MSCOM) for Windows 95/98/NT4 SP3 (or later) is available.
Please refer to the MSCOM instruction manual for more information Microelettrica Scientifica.
