Network Device Installation Manual

Documentation Number 485T1995 Manual 11
B&B Electronics -- PO Box 1040 -- Ottawa, IL 61350
PH [phone] -- FAX [phone]
You can then use the 485T Tester to monitor the data that is
being sent or received on your network. If you have a datascope or
a computer running a datascope-like program you can connect it to
the RS-232 DATA OUT connector on the 485T. A typical program
would be BreakOut II which is available from B & B Electronics. The
RS-232 DATA OUT connector is wired as a DTE with data output on
pin 2. Pin 4 is connected to pin 5 and pin 6 is connected to pins 8
and 20 for handshake loopback. Pin 7 is ground and there is no
connection to pin 3.
NOTE: If the data you receive is garbled, you may have the A &
B connectors backwards. Try reversing them.
With the 485T connected and the THRESHOLD pot turned to
zero (full clockwise), any RS-422/485 data on the network will
appear as RS-232 data at pin 2 of the RS-232 DATA OUT jack. If
you have a four-wire network you can only view one pair of lines at a
time. This means that you can only see data transmitted from that
node or data received by that node, not both at the same time. On a
two-wire node (RS-485) you can see both received and transmitted
data at the same time.
NOTE: Your datascope must be able to receive data at the
same baud rate, etc. as the data that is transmitted on the RS-
422/485 network.