5-2
5.1.1 Common specifications
Items Specifications
Protocol FGI-BUS Modbus RTU FRENIC Loader
Compliance Fuji general-purpose
inverter protocol
Modicon Modbus
RTU-compliant
(only in RTU mode)
Dedicated protocol
(Not disclosed)
No. of supporting
stations
Host device: 1
Inverters: up to 31
Electrical
specifications
EIA RS-485
Connection to RS-485 8-wire RJ-45 connector
Synchronization Start-Stop system
Transmission mode Half-duplex
Transmission speed 2400, 4800, 9600 or 19200 bps
Max. transmission
cable length
1,640 ft (500 m)
No. of available
station addresses
1 to 31 1 to 247 1 to 255
Message frame format FGI-BUS Modbus RTU FRENIC loader
Frame
synchronization
Detection SOH (Start
Of Header) character
Detection of no-data
transmission time for
3-byte period
Start code 96H
detection
Frame length 16 bytes (fixed) in
normal transmission
8 or 12 bytes in
high-speed
transmission
Variable length Variable length
Max. transfer data Write: 1 word
Read: 1 word
Write: 50 words
Read: 50 words
Write: 41 words
Read: 41 words
Messaging system Polling/Selecting/Broadcast Command message
Transmission
character format
ASCII Binary Binary
Character length 8 or 7 bits
(selectable by the
function code)
8 bits (fixed) 8 bits (fixed)
Parity Even, Odd, or None
(selectable by the function code)
Even
Stop bit length 1 or 2 bits
(selectable by the
function code)
No parity: 2 bits
Even or Odd parity:
1 bit
1 bit (fixed)
Error checking Sum-check CRC-16 Sum-check