174
(3) To increase communication speed
Communication speed can be increased by checking the following items again.
*1
For Page 173, Section 8.3.8 (2), correct the settings in the CPU module of a master station and program.
Item
Description
Sequence scan of a CPU module
*1
Shortening sequence scan time can increase communication speed.
For causes extending sequence scan time, refer to the following.
QnUCPU User’s Manual (Function Explanation, Program Fundamentals)
Transient transmission process
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.
(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.
Link scan time
Minimizing the points of the RX/RY setting and RWw/RWr setting shortens link
scan time, resulting in increased communication speed.
Data transfer to modules in different
networks
Correct the routing parameters and minimize the number of networks where
data is transferred.
Item
Description
"Service Processing
Setting” in the PLC
parameter
*1
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
*1
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))