NCR NCR7454 manual Serial Ports, Hardware Monitor

Chapter 1: Product Overview 1-13

Serial Ports

The Summa POS Motherboard provides two RS-232 ports (9-pin D- shell connectors, Ports 1 and 2) directly on the Motherboard and supports two additional RS-232 ports. Ports 3 and 4 require an optional harness connection to the Motherboard. Ports 1 and 3 can be supplied with +12 V DC on Pin 9 when properly set up in the BIOS. The total power drawn by Ports 1 and/or 3 must be no greater than 1 amp at +12 V DC. Refer to the following table for RS-232 pinout information.

The BIOS provides flexibility in mapping resources. However, a fully- loaded system (2 PCMCIA cards that require IRQs, four serial ports in use, USB in use, parallel port in use, and MSR) may not have enough available IRQs to support all serial ports. Use a USB serial port expander to overcome this PC architecture limitation.

RS-232 DB-9 Male Connector Pinout

Pin	Port A	Port B
1	DCD	DCD
2	RXD	RXD
3	TXD	TXD
4	DTR	DTR
5	GND	GND
6	DSR	DSR
7	RTS	RTS
8	CTS	CTS
9	RI or +12*	RI

* If Port 1 or 3 is powered, pin 9 will be +12 V.

Hardware Monitor

The hardware monitor generates an interrupt to the system whenever any of the internal voltages used by the system processor goes above or below the acceptable operating range. An interrupt is also generated when the temperature of the Processor exceeds safe levels. Software can use this indication to slow or stop the system and/or force a reset.