Mitsubishi Electric MELSEC Q Series Reference Manual page 125

(2) Measurement result of the communication speed
The following table lists the time that takes until a file is read from a request source device to a request destination
device.
Size of a file to be communicated
1K byte
50K bytes
100K bytes
1M byte
(3) To increase communication speed
Communication speed can be increased by checking the following items again.
Item
Sequence scan of a CPU module
Transient transmission process
Link scan time
Data transfer to modules in different
networks
Shortening sequence scan time can increase communication speed.
For causes extending sequence scan time, refer to the following.
*1
QnUCPU User's Manual (Function Explanation, Program Fundamentals)
Communications using the IP packet transfer function are performed with
transient transmission. Taking one of the following actions can increase
communication speed.
(1) Increase the frequency of transient transmission
The following actions can increase the frequency of transient transmission
(the amount of processes per transient transmission). Consequently, the
frequency of communications using the IP packet transfer function
increases, resulting in increased communication speed.
Item
"Service Processing
Setting" in the PLC
parameter
Executing the COM
instruction
(2) Decrease the number of other transient transmission
Decreasing the number of other transient transmission ensures the
processing time of the IP packet transfer function; therefore,
communication speed can be increased.
Minimizing the points of the LB/LW setting and LX/LY setting shortens link scan
time, resulting in increased communication speed.
Correct the routing parameters and minimize the number of networks where
data is transferred.
CHAPTER 4 FUNCTIONS
Time
10ms
300ms
500ms
5000ms
Description
Description
Increasing the frequency of a service process in "Service
Processing Setting" of the PLC parameter increases the
frequency of transient transmission. Note, however, that
increasing the frequency of a service process affects sequence
scan time. ( QnUCPU User's Manual (Function
Explanation, Program Fundamentals))
Executing the COM instruction on a program and executing a
service process at any timing other than an END process
increase the frequency of transient transmission.
( MELSEC-Q/L Programming Manual (Common
Instructions))
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