IMP Pumps NMTC module - Manual (Page 6)

6
Modbus specifications
Data protocol
Modbus RTU
Modbus connector Screwless terminals
2+1 pins. See section 7.3 “Connection to
Modbus”.
Modbus connection
type
RS-485
Modbus wire
configuration
Two-wire + common
Conductors: A, B and COM (Common).
See section 7.3 “Connection to Modbus”.
Communication
transceiver
Integrated, 1/8 of
standard load
Connect either via passive taps or daisy chain.
Maximum cable
length
1200 m See section 7.5 “Termination”.
Slave address 1-247
Default is 245, settable over Modbus. See
section 7.4 “Speed, parity and address”.
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.
Ethernet specifications
Ethernet connector
RJ-45 10BASE-T, 10Mbit/s connection.
Connection type and
services
-
Web server (port 80)
-
Firmware update over web interface
-
Optional Modbus RTU over TCP/IP
Default IP address 192.168.0.245 192.168.0.246 for right twin pump.
Ethernet visual
diagnostics
LED1 / LINK
Slowly blinking when module is powered,
permanently lid when link established.
LED2 / ACT
Flashing yellow when data reception detected.
Combined (OR) with Modbus data reception
indication.