User's Manual

64
7.1 Conversion Circuit
Examples of the level conversion circuit are shown as a reference, which is just for the
confirmation of system operation. This example does not guarantee the operation under
users’ actual operation environment.
7.1.1 RS-232C Level Converter
Wire the control line when necessary. Tie down unused input pin(s) to GND and leave the
485ENB pin open.
Figure B–1: RS-232C Level Conversion Circuit
7.1.2 RS422 Level Converter
Wire the output terminator (100 ohm) of the RS422 line driver, the input terminator (100
ohm) of the receiver, the input pull-up (1k ohm) and the input pull-down (1k ohm), when
necessary.
Provide a surge absorber (e.g. Z2012 made by Ishizuka Denshi) when long RS422 line is
used or there is much noisy environment, etc.
Figure B–2: RS422 Level Conversion Circuit