Description

NTCDMA-RS485 is a Type-II PCMCIA card which adds a single multi-protocol serial interface using a Zilog 85230 compatible SCC controller. The port can be configured as RS-422 by connecting a 100 Ohm resistor, or as RS-485 by connecting a 60 Ohm resistor. The SCC can support asynchronous formats, byte-oriented synchronous protocols such as IBM Bisync, and bit-oriented synchronous protocols such as HDLC and SDLC. The SCC also offers internal functions such as on-chip baud rate generators, and digital phase-lock loop (DPLL) for recovering data clocking from received data streams.

Because the PCMCIA 2.1 standard does not support direct memory access (DMA), the NTCDMA-RS485 supports only interrupt-driven communications. To compensate for the lack of DMA, the card is equipped with 1024-byte transmit and receive FIFOs. With the FIFOs enabled, data can be moved to and from the SCC in large blocks, providing for high data throughput and low interrupt overhead.

The NTCDMA-RS485 provides standard data rates of 0.6, 1.2, 2.4, 4.8, 9.6, 19.2, 38.4, and 57.6 kbps. Higher data rates up to 2.45 Mbps are achievable subject to the limitations of the cabling and the interrupt response time of the host computer. The NTCDMA-RS485's top speed is limited by the 85230 SCC, and with an upgraded crystal the card can reach speeds to 4 Mbps.

All necessary software is included to install and configure the card for use with DOS/Windows 3.x, Windows 95/98, and OS/2. In addition, our frame-level HDLC and Bisync driver, SYNCDRIVE, is included free.

 Specifications

BUS INTERFACE: PCMCIA Card Specification 2.1

DATA RATE:

2.45 MBPS or 4.0 Mbps with an upgraded crystal.
Contact a Interworld sales engineer for information on upgraded crystals available for the NTCDMA-RS485

PORTS: 2

CONNECTOR:

Standard DSUB-25 MALE connector via a pigtail cable off the Type II PCMCIA Card

Pin 1: Chassis ground Pin 2: Transmit Data     Pin 3: Receive Data Pin 4: Request To Send Pin 5: Clear To Send Pin 6: Data Set Ready Pin 7: Signal Ground Pin 8: Carrier Detect Pin 9: Receive Clock In - Pin 10: Carrier Detect - Pin 11: Receive Clock Out - Pin 12: Transmit Clock In - Pin 13: Clear to Send -

Pin 14: Transmit Data - Pin 15: Transmit Clock In- Pin 16: Receive Data- Pin 17: Receive Clock In Pin 19: Request To Send- Pin 20: Data Terminal Ready Pin 21: Sync In (RS-422) Pin 22: Data Set Ready- Pin 23: Data Terminal Ready- Pin 24: Transmit Clock Out Pin 25: Chassis Ground

OS SUPPORT:  DOS, Windows 3.1x, Windows 95/98, OS/2

INCLUDED SOFTWARE: SYNCDRIVE included for DOS, Windows 3.1/95/98 and OS/2.

INCLUDED ACCESSORIES: NTCDMA-RS485 cable.