NAiS FP Series, User Manual

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FP
Σ
10.5 PLC Link Response Time
10 - 25
10.5.2 Shortening the Transmission Cycle Time When There are Stations
That Have not been Added to the Link
If there are stations that have not been added to the link, the Tlk time (link addition
processing time) will be longer, which causes the transmission cycle time to be longer.
T max. = Ts1 + Ts2 + - - - - + Tsn + Tlt + Tso + Tlk
Tlk = Tlc (link addition command sending time) + Twt (addition waiting time) + Tls (link error stop command
sending time) + Tso (master station scan time)
If the SYS1 instruction is used to shorten Twt in the above formula, the increase in the
transmission cycle time can be minimized.
Example of setting the SYS1 instruction
SYS1 MPCLK1T0, 100
Function description: Changes the waiting time for a link to be added to the PLC link
(default value = 400 ms)
In the above, the waiting time is set to 100 ms.
Key words: Setting for the No. 1 key word: PCLK1T0
Allowable setting range for the No. 2 key word: 10 to 400 (10 ms to 400 ms)
Notes
Precautions concerning settings:
The above instruction should be set so that it is executed at
the beginning of the program, at the rise of R9014, and the
same value should be set for all of the PLCs being linked.
Executing the above instruction does not change any of the
system registers.
The SYS1 instruction should be set to a value at least twice
that of the maximum scan time for any of the PLCs connected
to the link.
If a short value has been set, there may be PLCs that cannot
be added to the link even if the power supply to that PLC is on.
However, the shortest time that can be set is 10 ms.
If there are any stations that have not been added to the link,
the setting should not be changed as long as a longer link
transmission cycle time does not cause any particular
problems.