FujiFilm FRENIC5000G11S Series, Technical Information

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Chapter 2
4. Standard RS-485 Interface
2
4.4 Transmission method
The polling/selecting system is applied to the response
message feature. The inverter is always waiting the selecting
(writing request) and polling (reading request) from the host
unit.
When the inverter receives a request frame from the host
during waiting state and judges for it to be a correct receiving,
the inverter processes for the request and returns an affirm
response frame (in a case of polling, returning the data
together with the affirm response frame). If judging it not to be
normally received, the inverter returns a negative response
frame. Further, in a case of broadcast (selecting all terminals
in a lump), the inverter does not return the response.
Polling
Request frame
Host
Reading request
Inverter
Re Data
Response frame
Selecting
Request frame
Host
Writing r Data
Inverter
Response
Response frame
Broadcast
Request frame
Host Writing r Data
Inverter
Description) Broadcast (selecting one lump of all terminals)
A frame set with station address of 99 is treated by all invert-
ers as broad cast. By using broadcast, operation commands
and frequency command can be give all the inverters in a
lump. (The writing of S01 - S06 ['W', 'E' commands] in the
standard frame and 'a' - 'f' and 'm' commands in the option
frame are only valid.)
4.4.1 Transmission frame
In the transmission frames, there are standard frames that can
use all communication functions and option frames that are
limited to the command and monitoring to inverter but can
perform high-speed communication.
In both standard frame and option frame, all characters
(including BCC) configuring the frame is expressed with ASCII
code.
The lengths of transmission frames become shown in the
following table.
Sort of frame Frame length
Standard frame Selecting Request 16 bytes
Response 16 bytes
Polling Request 16 bytes
Response 16 bytes
Option frame Selecting Request 12 bytes
Response 8 bytes
Polling Request 8 bytes
Response 12 bytes
4.3.4 Example of noise prevention
The malfunction such as communication error may be occured
by the noise generated the inverter. In such case, connect
ferrite core or capacitor.
Host unit
TRD+
TRD-
FG
Pass through or
wind 2-3 turns so as
in the same phase
Inverter
DXA
DXB
SD
G
Ferrite core
Capacitor
0.01
µ
F 1000V
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