User`s manual

CP-132 Series Connection Cable and Cable Wiring
5-3
RS-485 pin outs for Industio CP-132 Series:
Pin Signal
1 Data-(A)
2 Data+(B)
5 GND
See the section “RS-485 Programming” of the chapter “Serial Programming Tools” for more RS-485
programming details.
Impedance Matching and Termination Resistors
For RS-422/485 serial communications, when an electrical signal travels through two different resistance
junctions in a transmission line, the impedance mismatch will sometimes cause signal reflection. Signal
reflection causes signal distortion, which in turn will contribute communication errors. The solution to this
problem is to establish the same impedance at the line ends as in the line itself by terminating them with
resistors.
Industio CP-132 already installs the resistors on board for your convenience, indicated as follows. The value of
the termination resistor should equal the characteristic impedance of the transmission line. Resistors should be
added near the receiving side.
NOTE
Stands for termination resistor near the
receiving side
Industio CP-132 Series Board