IMP PUMPS NMT Max C - Connection to Modbus; Speed, Parity and Address; Termination; Register Block Overview

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For short wiring and/or low baud rate, interface can operate without termination. However it is recommended
that termination (~150 ohm resistor) is added on both ends of bus wiring. There are wiring length limits
regarding to speed and termination:
Maximum speed [baud]
Maximum cable length [m]
38400
1200, terminated cable
9600
1200
19200
500
38400
250
NOTE: Any branch/derivative cable is considered unterminated. Keep them short, below 250m combined for
maximum speed and reliability.
7.6. REGISTER BLOCK OVERVIEW
NMTC
Modbus RTU registers are grouped in the following register blocks:
Start address
Register block
Readable/Writeable
Description
001
NMTC configuration
R/W
Configuration of the NMTC module.
021
NMTC status
R
Status registers for the NMTC
module.
101
Pump control
R/W
Pump control registers.
201
Pump status
R
Status data from the pump.
301
Pump data
R
Measured data from the pump.
All addresses contain 16 bit (one Word) registers. Some are bit interpreted while others are combined
for a 32 bit value.
NOTE: All register addresses are 1-based. Address 001 is thus transmitted over bus as 0x0000.
7.7. NMTC CONFIGURATION REGISTER BLOCK
Registers in this block are read with either function codes 0x03 or 0x04. They can be written as
holding registers with function codes 0x06 and 0x10.
NOTE: All values in this block are stored in nonvolatile memory immediately after write.
NOTE: See section “4.3 Module mode selection ” and use Mode 8 or 9 to restore default settings if you
cannot access the controller after writing to these registers.