Tiny Addressable Serial Converter
ICP DAS CO., LTD.
User Manual, Ver. 1.3, Apr. 2018, Page: 16
2.7
Wiring Notes
RS-485 Wiring Connection
Note:
1. usually, you have to connect all signal grounds of RS-485 devices together to reduce
common-mode voltage between devices.
2. Twisted-pair cable must be used for the DATA+/- wires.
3. Both two ends of the cable may require a termination resistor connected across the two
wires (DATA+ and DATA-
). Typically 120 Ω resisters are used.
4. The Data+ and B pins are positive-voltage pins, and Data- and A pins are negative-voltage
pins in the above figure. The B/A pins may be defined in another way depending on devices,
RS-232 Wiring Connection
Note:
1. For 3-Wire RS-232
connections, it is
recommended that unused
signals such as RTS/CTS and
DTR/DSR are shorted, since
some systems may still check
the status of CTS and DSR.
2. FGND is the frame ground
that provides a path to earth
ground for ESD protection.
