Mitsubishi QJ71E71-100 Series, Руководство пользователя

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MELSEC-Q
4 WHEN THE QCPU ACCESSES THE OTHER STATION PLC USING THE
DATA LINK INSTRUCTION
4
4.2 Precautions for Accessing Other Stations
The following describes precautions when accessing other stations via the Ethernet
module using the data link instructions.
(1) Executing multiple instructions at one time (common to the data link
instructions)
(a) When accessing multiple communication request destination stations (other
stations) from the same communication request station at one time, change
the target channel number of the communication request source station for
each communication request destination station.
(b) When accessing other stations using the same channel number, access the
next station after the last access to other station is completed.
(c) For mutual accesses between the communication request station and the
communication request destination station, change the target channel
number of the communication request station for each instruction.
If the access destination stations (communication request destination station)
are different, a maximum of eight instructions can be executed at one time as
long as the channel numbers (1 to 8) designated in the control data of each
instruction do not overlap.
(2) Setting the arrival monitoring time of the control data storage
device
For the arrival monitoring time designation area of the control data storage
device, set the monitoring time that is equal to or greater than the TCP resend
timer value set with the initial processing parameters.
When the monitoring time is equal to or less than the TCP resend timer value,
the TCP resend timer value is set as the arrival monitoring time. ( 1)
(When the setting value is less than or equal to the TCP resend timer value, the
arrival monitoring timer equals the TCP resend timer value.)
1 Although the units of setting values for the TCP resend timer (setting value
units: 0.5 s) and the arrival monitoring timer (setting value units: s) are
different, the TCP resend timer value is used as is.
(3) Checking the execution result of each data link instruction
The execution result (completion status) of each data link instruction is stored in
the areas shown as binary values.
After the execution of an instruction is completed, read the execution result from
the storage area and verify either normal or abnormal completion.
Stored value at normal completion : 0
Stored value at abnormal completion: Other than 0 (error code)
When an error code that indicates abnormal completion is stored, take an action
by seeing the "Troubleshooting" section in the User's Manual (Basic).