IMPPUMPS NMT MAX Series - Page 27

27
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3.4.6 MODBUS
AvailableonlyonNMT(D)MAXCpumps.
Modbus specification
Dataprotocol ModbusRTU
Modbusconnector Screwlessterminals 2+1pins.SeeNMTCmodulemanual.
Modbusconnection
type
RS‐485
Modbuswire
configuration
Two‐wire+common Conductors:A,BandCOM(Common).
SeesectionSeeNMTCmodulemanual.
Communication
transceiver
Integrated,1/8of
standardload
Connecteitherviapassivetapsordaisychain.
Maximumcable
length
1200m SeesectionSeeNMTCmodulemanual.
Slaveaddress 1‐247 Defaultis245,settableoverModbus.SeeNMTC
modulemanual.
Linetermination  Notpresent Lineterminationisnotintegrated.Forlow
speed/shortdistance,terminationcanbeomitted.
Otherwise,terminatethelineexternallyonboth
ends.
Supported
transmissionspeeds
1200,2400,4800,9600,
19200,38400baud
SettableoverModbusregister[default=19200].
Startbit 1 Fixed.
Databits 8 Fixed.
Stopbits  1or2 1stopbitminimum,upto2whenparitynot
enabled[default=1]
Paritybit Even/odd/none [default=Even]
Modbusvisual
diagnostics
LED2  Flashingyellowwhendatareceptiondetected.
Combined(OR)withEthernetACTfunction.
Maximumnumberof
Modbusdevices
247 LimitedbypossibleModbusaddressesto247.1/8
nominalloadenables256devices.
MaximumModbus
packetsize
256bytes  Includingaddress(1)andCRC(2)bytes.
Isolation Commonground(COM)
withSET1,SET2and
SET3.
Modbussharescommongroundwithothersignals.
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