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Chapter 7 Communication function
7-101
9
In RS-422/485 communication system especially linked with many slave stations as in Ex.1, since
transmission channels of slave stations are connected to receiving channel of master station via one
line, normal transmission/receiving of data is impossible if orderly communication is not performed.
Thus, surely prepare the program for master station to request orderly transmission/receiving of data.
[Figure 7.19] describes the case that data crash occurs in multi-drop communication system. Because
TX/RX lines of communication devices applied in communication share one communication cable as in
the figure, normal communication can’t be performed due to data crash if simultaneous transmission is
applied by several stations. [Figure 7.19] shows an example of data crash in communication line when
transmission is applied by slave stations 2 & 3 at a time.
[Figure 7.19] Data crash in multi-drop system
Master
Slave 1
Slave 2
Slave 3
Slave 4
Data crash
Response frame 3
Response frame 2
(a)Data crash in RS-485 system.
Содержание GLOFA-GM Series
Страница 355: ...Appendix A 12 A 3 Dimensions of appearance G3L CUEA Unit mm 118 0 130 5 35 0 250 0 ...
Страница 356: ...Appendix A 13 G4L CUEA 107 0 121 5 35 0 135 0 ...
Страница 357: ...Appendix A 14 G6L CUEB G6L CUEC Dimensions of G6L CUEB G6L CUEC are identical with each other 81 1 90 0 35 0 110 0 ...