Product manual

Serial Solutions Range Product

Manual

• To achieve RS485 Half Duplex communications, using two wires for communication, Pins 1 and 6, 2

and 7 must be physically shorted.

• Once your wiring is setup, you will also need to set the card to FULL or HALF Duplex mode in the

software. For further details, see Section 3: Product Configuration.

9.3. Terminating Resistors

RS422 and RS485 lines should be terminated at the end of the main branch of the RECEIVER, in the cables

characteristic impendence. These terminating impendence’s stop echoes caused by the serial data being

reflected back at the cable ends. It is not necessary to terminate the transmitter end of the twisted pair.

The AT Dual Port RS422/485, Opto Isolated AT Dual Port RS422/485 and AT Velocity RS422/485 cards

have the correct 120 ohm (nominal) terminating resistors for the RXD twisted pair line and the CTS twisted

pair line fitted on the RS422/485 card for both the serial ports on the card.

There is no need to add any more at the PC end.

The terminating impendence’s shown later in the wiring diagrams are automatically provided by the on board

resistors and do not have to be added by the user.

9.4. Storage and Operating Environment Guidelines

Storage

Temperature: -10 ˚C to +70 ˚C

Humidity: 8% to 95% non-condensing

Operational

Temperature: 0˚C to +70˚C

Humidity: 20% to 75% non-condensing