The 1403-NSC is a smart communication card from Allen-Bradley/Rockwell Automation. The card is used in an Allen-Bradley Powermonitor II Master Module as a dual-port communication plug accessory providing the Powermonitor with communication ports (2 of which are active). The Allen-Bradley PLC R I/O network is interfaced with the Powermonitor II through one port of the 1403-NSC while the other active port is dedicated to the RS-232/ RS-485 EIA standards. The 1403-NSC does not require hardware configurations. Additionally, the smart communication card features a 1,200 to 19,200 baud rate (serial) and a 57,600 to 230,000 baud rate (R I/O). The communication ports on the 1403-NSC have an isolation of 500 Volts.

The RS-485 and the R I/O configurations employ a daisy chain topology which should be terminated at each end to prevent end reflections. The cable resistance, the frequency, and the baud rate should be considered during termination. The master module is used to define the baud rate, address, and communication format for the 1403-NSC Smart Communication Card. The face of the communication card features 3 LED indicators (TXD, RXD, R I/O). Although the 1403-NSC can accept 12 cable connections, only 10 slots are usable. Slots 8 to 10 are for the RS-485 connections and it accommodates a Belden 9841 2 shielded cable with a maximum length of 4,000 feet. The next group, Slots 4 to 7, are meant for RS-232 connections. The slots accommodate a Belden 9608 3-wire shielded cable with a maximum length of 50 feet. The other Slots, 1 to 3, are for the R I/O connections. They accommodate a 1770-CD twin-axial cable. The RS-485 communication line must include a 150 ohms ¼  watts terminating resistor. On the RS-I/O communication format, a 150 ohms ¼ watts terminating resistor must be used when the baud rate is set between 57,600 and 115,200 baud. When the baud rate is at 230 to 400 baud, the terminating resistor should have a rating of 84 ohms ¼ watts.