B&B Electronics 485T manual

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.

Documentation Number 485T1995 Manual	11
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