Specifications Of Rs-485 Communications - Fuji Electric FRENIC-AQUA series User Manual

2.1

Specifications of RS-485 Communications

Table 2.1 shows the specifications of RS-485 communications.
Item
Protocol
Complying with
No. of supporting
stations
Physical level
Connection to
RS-485
Synchronization
method of character
Transmission mode
Transmission speed
(bps)
Maximum
transmission cable
length
No. of available
station addresses
Message frame
format
Synchronization
method of
transmission frames
Frame length
Maximum transfer
data
Messaging system
Transmission
character format
Character length
Parity
Stop bit length
Error checking
2.1 Specifications of RS-485 Communications
Table 2.1 RS-485 communications specifications
FGI-BUS
Fuji general-purpose
inverter protocol
Host device: 1
Inverters: up to 31
EIA /RS-485
Connect using the RJ-45 connector or terminal block
Start-Stop system
Half-duplex
2400, 4800, 9600, 19200 and 38400
500 m
1 to 31
FGI-BUS
Detection SOH (Start Of
Header) character
(SOH 01 )
H
Normal transmission:
16 bytes (fixed)
High-speed transmission:
8 or 12 bytes
Write: 1 word
Read: 1 word
Polling/Selecting/Broadcast
ASCII
8 or 7 bits (selectable by
the function code)
Even, Odd, or None (selectable by the function
code)
1 or 2 bits (selectable by
the function code)
Checksum
2-1
Specification
Modbus RTU Loader commands
Modicon Modbus Special commands
RTU-compliant (only in dedicated to inverter
RTU mode only) support loader software
(not disclosed)
1 to 247 1 to 255
Modbus RTU Loader command
Detection of no-data Start code 96H
transmission time for 3 detection
byte period
Variable length Variable length
Write: 50 words Write: 41 words
Read: 50 words Read: 41 words
Command message
Binary Binary
8 bits (fixed) 8 bits (fixed)
Even
No parity: 2 bits 1 bit (fixed)
Even or Odd parity:
1 bit
CRC-16 Checksum