IC832A & IC833A - 1008 page 4/x
p/n 8024 Rev 001
Black Box Corporation - 1000 Park Drive - Lawrence, PA 15055-1018
Tech Support and Ordering: 724-746-5500 - Fax: 724-746-0746
To contact us about Black Box products or services:
485USBTB-4W Wiring
IC832A Loop Back Test
IC832A Back to Back
Test
•
Loopback TDA(-) to RDA(-) and TDB(+) to
RDB(+) as shown in the diagram above.
•
Using Hyper Terminal or similar program,
connect to the appropriate COM port. Set the
desired baud rate. Ensure Hyper Terminal local
echo is OFF.
•
Transmit data. If the same character string is
returned, the test is good.
•
This converter is used for RS-485 4-Wire Systems.
•
Loosen the screws to open the Terminal Block lead
clamps for the TDA(-), TDB(+), RDA(-), RDB(+), and
GND terminals.
•
Insert the RS-485 2-Wire signal leads in accordance
with the diagram above. The TB will accept 28 to 16
AWG wire.
•
Tighten the screws to close the TB lead clamps. Ensure
the clamps hold the leads securely. However, do not
over tighten.
•
Bias is provided by 4.7K
Ω
pull-up and pull-down
resistors.
•
If termination is required, it must be installed externally.
In most cases, termination is not required.
•
During operation, the receiver is always active.
•
Due to the circuit configuration, a loop back test
is not possible with this model. However, two
converters can be used in a back to back
configuration.
•
Wire the converters as shown above.
•
Using Hyper Terminal or similar program,
connect to the appropriate COM ports. Set the
desired baud rate.
•
Transmit data. If the same string is received on
the distant end, the test is good.
