User`s manual

341
CHAPTER 14 DATA COMMUNICATIONS USING EXTERNAL DEVICE AND PROGRAMMABLE CONTROLLER CPU M : N
CONFIGURATION
14
14.3 Examples of Procedure for Data Communications with the Programmable Controller CPU
5. The external device that accepts the line usage right transmits a response message to the external
device that passed it the line usage right.
6. The external device that accepted the line usage right by transmitting a response message
performs processing beginning from step 2.
7. When line usage time of the external device that currently has the line usage right exceeds the
maximum data communications time.
a) The external device of the next station No. transmits all external devices general report data and
obtains the line usage right and performs step 2.
b) The other external devices check if all external devices general report data was received. If the data
was received, the external device performs step 3.
If the data was not received, the next external device transmits all external devices general report data
and obtains the line usage right and performs step 2. The other external devices perform step 7-b).
*1
*1
(1C) (1B) (ZZ) (CD)(2)(;)
(1C)
31H 43H
(1B)
31H 42H
(:)
31H 43H 31H 42H 5AH 5AH 43H 44H32H3BH
3AH
Transmission destination station No. Transmission source station No.
Transmission destination station No. Transmission source station No.
Command Message wait Sum check code
Message of
4 above
External device
that transfers line
usage right (1BH)
Message of 5
External device
passed line usage
right (1CH)
Command "ZZ" is command for
description purposes.
The user should select the command
that transfers/accepts the line usage right.
(1F)
31H 46H
(1C)
31H 43H
(ZZ)
5AH 5AH
(0A)
30H 41H30H
(0)
3BH
(;)
*2*1
External device
that obtains the
line usage right
(1CH)
Station No. for all external
devices general report.
See *1 of step 5.
*1
*2
Transmission designation station No. Transmission source station No. Command Message wait Sum check code