Manualshelf

User`s manual

ManualsBrandsMitsubishi ManualsComputer equipmentQJ71C24/-R2
341342343344345346347348349350
342
14.3.2 Data communications between programmable controller CPU
and external devices by designating a master station and
slave stations
One of the external devices is made the master station and the other external devices communicate data with the
programmable controller CPU after obtaining permission from the master station.
The following uses an example to describe the procedure when external devices communicate data with the
programmable controller CPU.
In this example, after the start of data communications between external devices and the programmable controller
CPU, the external devices perform a maximum data communications time time-out check. Slave station external
devices that are not communicating data with the programmable controller CPU check if the external device that
completed data communications with the programmable controller CPU transmitted a communications complete
report.
In the following descriptions, the external device with the lowest station No. (1BH) is assumed to be the master station
and the other external devices are assumed to be slave stations.
: External device that obtained the line usage right
Permission
granted
response
Response
Communications
request
General report to
start and end data
communications
between master
station and
programmable
controller CPU
Start
End
Master station
external device
Slave station
external device 1
Communications
request
Communications
complete report
TIme
Slave station
external device 2
Slave station
external device m-1
Communications
request
Permission
granted
response
Permission
granted
response
Communications
complete report
Response
Data communications
with programmable
controller CPU
Data communications with programmable controller CPU
CPU
CPU CPU CPU
C24C24C24C24
§
21
External device
(Station No.: 1BH)
(Station No.: 0H)
(Station No.: 1H) (Station No.: 2H) (Station No.: 15H)
External device
(Station No.: 1CH)
External device
(Station No.: 1DH)
External device
(Station No.: 1EH)
Master station
C24: Q series C24, QC24 (N), UC24
(Before 2)
(after 2)
§