User Manual of EM730/EM730E Series Inverter
340
Table 4-34 Correspondence between Time Interval and Baud Rate (t
adjust
=1ms)
Correspondence
between Time
Interval and
Baud Rate
(t
adjust
=1ms)
Starting and
ending time
interval
T
interval
(t
adjust
)
Exception
interval T
exception
(t
adjust
)
Remarks
4800
8
4
The idle level of 3ms or less is allowed
for a normal frame. When the idle level
is 8ms or greater, it indicates the end of
a frame of data.
9600
4
2
The idle level of 1ms or less is allowed
for a normal frame. When the idle level
is 4ms or greater, it indicates the end of
a frame of data.
19200
2
1
The idle level of less than 1ms is
allowed for a normal frame. When the
idle level is 2ms or greater, it indicates
the end of a frame of data.
Higher
1
1
When an idle level of 1ms appears, it
indicates the end of a frame.
t
0
Frame 1
Frame 2
Frame 3
At least 3.5
characters
At least 3.5
characters
3.5 characters
4.5 characters
< 1.5 characters
＞
1.5 characters
Except
ional
frame
Normal
Fig. 4-22 Schematic Diagram of Normal and Exceptional Data Frames
11.4.2
Data frame processing
Upon receiving a frame data, the system will first perform preprocessing to determine
whether it is a legal frame sent to this machine and check whether the data is correct, followed
by final processing. If the received frame is not legal, the data will not be sent back. If the
received frame is legal but incorrect, the corresponding exceptional message frame will be sent
back.
Legal frame: Meet the address (local or broadcast) and length (not less than 3)
requirements.
Correct frame: It is a legal frame with a correct memory address. The memory content is
within the defined range and can be processed at present.
