Yamaha ERCX Computer Hardware User Manual


 
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CHAPTER2 Ethernet Unit
2-7 Using TELNET
Communicating by TELNET (remote operation) allows loading and editing point or
program data and operating the robot just the same if connected through an RS-232C
port.
Commands are easy to understand because they are identical to RS-232C communica-
tion commands.
2-7-1 Difference between TELNET and RS-232C communications
TELNET and RS-232C both perform the same processing. However, they use different
communication formats. This means that one format might not match your own particu-
lar system needs or objectives, so you should get a good understanding of their different
features before incorporating them into your system.
TELNET
Easily connects to different types of systems. Can handle one versus multiple device
communications.
Allows remote communications since it connects between separate systems.
Basically not usable for real-time processing since real-time operation is not guaran-
teed.
RS-232C
Basically handles one party to one party (or device) communications.
Designed for communications between devices in close proximity.
Operates largely to real-time specifications.
Ethernet communications protocol specifications do not guarantee real-time opera-
tion. So relying only on the Ethernet in situations such as robot emergency stop can be
extremely dangerous. Install safety interlock circuits using the emergency stop termi-
nal in the parallel I/O of the controller to ensure quick and effective emergency stops.