87

Corporation

SIGNAL PROCESSING EXCELLENCE

SP304 CONFIGURATIONS IN LOOPBACK MODE

One-Channel Full Duplex RS-232 &

One-Channel Full Duplex RS-422

Opposite Drivers

Two-Channel Full Duplex RS-422

RS-232 LINE DRIVERS

RS-232 RECEIVERS

SELECT A = 1

SELECT B = 0

RS-422 LINE DRIVER

RS-422 RECEIVER

RS-422 LINE DRIVERS

RS-422 RECEIVERS

SELECT A = 1

SELECT B = 1

RS-422 LINE DRIVERS

RS-422 RECEIVERS

nects the driver outputs to the corresponding

receiver inputs, and switches the output pin to a

high impedance from V

outputs are left active for signal verification.

During loopback, the receiver inputs are tied to

ground via a 5k

Ω pulldown resistor. The re-

ceiver inputs can accept the full

±15V swings

with no interference to the loopback function.