Modbus RTU
Select appropriate Baud Rate, Address and parity setting.
Modbus serial interface connections are made at J2 terminals
labeled D+, D-, G and SH. The positive RS485 connection
is made to D+, the negative connection is made to D-. The
3-wire common connection is made to G and the shield drain is
connected to SH.
CAUTION
Do not connect shield drains to the "G" terminal.
Transceiver:
3-wire, half duplex (1/3 unit load)
Recommended maximum units per segment:
32
Baud rate(s):
9600, 19200, 38400, 57600, 115200 (default
38400) unless specified by end user
Address range:
1 – 255
Data format:
8-bit
Stop bits:
1
Parity:
Odd, Even or None
End of line termination:
Jumper selectable 120 Ohms or
none. Only use on end of line.
Biasing:
Jumper selectable 549 Ohms or none. Only one
device on the network should provide biasing.
Flow control:
none
The MODBUS implementation of the ELECTRA-flo supports the
use of function code 17, Report Slave ID.
When a message is sent to the meter requesting the slave ID,
the following message is returned: ELECTRA-flo G5
The meter will report data in decimal or HEX, depending on
the control system settings. The data must be converted from
decimal/HEX to ASCII in order to form the string.
Page 21
3/21 IOM-ELECTRA-FLO-INST
Nailor Industries Inc. reserves the right to change any information concerning product or specification without notice or obligation.
Function Codes Supported:
01 - Read Coil(s)
02 - Read Discrete Input(s)
03 - Read Holding Register(s)
04 - Read Input Register(s)
15 - Write Multiple Coils
17 - Report Slave ID
J2
BACnet
SH
G
D-
D+
8
7
6
5
