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Chapter 6 System configuration
6-4
6.1.4 Communication between PC and Cnet using interlocking channel
PC is operated as a master station of Cnet #1 ~ #N station.
PC and Cnet #1 station carry out communication through null modem via RS-232C channel.
PC as a master station carry out RS-422 communication with Cnet #2 ~ #N station via Cnet #1 station in
interlocking channel.
PC and Cnet #1 station perform RS-232C channel communication.
Communication between Cnet I/F modules is unavailable.
Cnet I/F module can connect with max. 32 stations (RS-422 communication).
Cnet #1 station is set to interlocking mode and Cnet # 2 ~ #N station are set to stand-alone mode.
All Cnet I/F modules shall be set to idedntical communication speed and operation mode.
[Figure 6.4] Dedicated modem communication with PC
Module setting
Type
RS-232C
RS-422
Channel mode
Station No.
Dedicated mode
PLC Cnet #1
Other company’s
dedicated mode
Not used
Interlocking
channel
1
Dedicated mode
Cnet #1~#31
Not used
Other company’s
dedicated mode
Stand-alone
channel
2~31
6.1.5 Interlocking & stand-alone channel communication
PC is operated as a master station of Cnet #1 ~ #N station.
PC as a master station carry out RS-422 communication with Cnet #2 ~ #N station via Cnet #1 station in
interlocking channel.
PC and Cnet #1 station perform RS-232C channel communication.
Communication between Cnet I/F modules is unavailable.
Cnet I/F module can connect with max. 32 stations (RS-422 communication).
Cnet #1 station is set to interlocking mode and Cnet#2 ~ #N station are set to stand-alone mode.
All Cnet I/F module RS-422 channels shall be set to identical communication speed and operation mode.
Cnet I/F module #2 ~ #N station communicate with PC via RS-422 channel and with monitoring device and
printer via RS-232C channel.
If monitoring device is GP or PMU, RS-232C of Cnet #N station can be set to dedicated mode
Stand-alone channel
Interlocking channel
Stand-alone channel
RS-232C Interface
MMI-PC
GLOFA-PLC
Cnet #2
GLOFA-PLC
Cnet #1
GLOFA-PLC
Cnet #N
RS-422 Interface