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4.1 Modbus RTU (RS-485) Communication Specifications
Modbus RTU (RS-485) communication specifications
Item
Specifications
Communication protocol
Modbus
Communication specifications
RS-485 interface
Communication method
Two-wire half-duplex asynchronous
System configuration
Single-Master-Multiple-Slave (SMMS)
Multi-drop
Data format
Modbus RTU mode (hexadecimal number (hex code))
Start bit: 1 bit
Data length: 8 bits (fixed) (LSB first)
Stop bit: 1 bit (fixed)
Parity bit: No parity (fixed)
Communication speed
Fixed at 9600 bps
Physical layer protocol
ANSI/EIA/TIA RS-485
Number of connected devices
Up to 32 units including master
Maximum transmission distance
1.2km when the communication speed is 9600 bps
Terminal resistance
120 Ohm
Can be set to on/off with switch
Error checking method
CRC-16
4.2 Modbus TCP (Ethernet) Communication Specifications
Modbus TCP (Ethernet) communication specifications.
Item
Specifications
Communication protocol
Modbus (TCP/IP)
Communication specifications
Ethernet
Communication interface
RJ-45 Ethernet IEEE 802.3af/ANSI X3.263
System configuration
Single-Master-Multiple-Slave (SMMS)
Port No.
No.502 (fixed: Modbus)
Communication speed
Max. 10 Mbps/100 Mbps
Physical layer protocol
100BASE-TX
Number of connected devices
Up to 254 units
Maximum transmission distance
100 m (distance up to the switching hub)
Applicable cable
Unshielded Twisted Pair (UTP) cable
(Category: 5e or higher)
IP address
192.168.100.1 (by default when shipped out)
Can be changed from the base unit or web browser.