WEG MVW3000 A0040 V023, Руководство пользователя

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MVW3000 | 9-27
9
Communication Networks
MVW3000 | 9-27
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Maximum distance: 10 meters.
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Signal levels according to EIA PADRÃO RS-232C.
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Three wires: transmission (TX), reception (RX) and return (0 V).
RS-485:
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This interface is used for multipoint connection (several slaves and the master).
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Maximum distance: 1000 meters (using shielded cables).
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Signal levels according to EIA PADRÃO RS-485.
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The EBA or the EBB expansion board, which have interface for the RS-485 communication, must be used.
Note: refer to the Item 9.2.4 RS-232 and RS-485 Physical Connection on page 9-23 which describes how to
make the physical connection.
Inverter Configurations in the Modbus-RTU Network
In order that the inverter be able to communicate properly in the network, besides the physical connection, it is
necessary to configure the inverter address, as well as the baudrate and the type of existent parity.
Inverter address in the Network:
It is defined through the parameter 308.
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If the type of serial communication (P0312) is configured for Modbus-RTU, it is possible to select addresses
from 1 to 247.
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Each slave in the network must have an address different from the others.
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The network master does not have an address.
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It is necessary to know the address of the slave even when the connection is point-to-point.
Baudrate and Parity:
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Both configurations are defined through the parameter P0312.
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Baudrates: 9600, 19200 or 38400 kbits/seg.
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Parity: None, Odd Parity or Even Parity
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All slaves, and also the network master, must use the same baudrate and parity.
Access to the Inverter Data:
Through the network, it is possible to access all the parameters and basic variables available for the MVW3000:
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Parameters: they are those existing in the inverters, whose visualization and modification is possible through
the Human-Machine Interface (HMI) (refer to the Parameter Quick Reference).
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Basic Variables: they are internal inverter variables, and they can only be accessed via serial communication.
It is possible through the basic variables, for instance, to change the speed reference, read the status, enable
or disable the inverter, etc. (refer to the
Item 9.2.2 Variable Code on page 9-17 ).
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Register: name used to represent either parameters or the basic variables during the data transmission.
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Internal Bits: they are bits accessed only by the serial, used for the inverter command and status monitoring.