Ampro Corporation 5001692A

Chapter 3 Hardware

34 Reference Manual CoreModule 420

Table 3-12. Serial Ports Pin/Signal Descriptions (J3, J9)

Pin # Signal DB9 # Description

1DCD* 1

Data Carrier Detect – Indicator to the serial port that external modem is

detecting a carrier signal (i.e., a communication channel is currently

open). In direct connect environments, this input will be driven by DTR

as part of the DTR/DSR handshake.

2DSR* 6

Data Set Ready – Indicator to the serial port that external serial

communications device is powered, initialized, and ready. Used as

hardware handshake with DTR1 for overall readiness to communicate.

3RXD

RX Data –

2Receive Data – Serial port receive data input is typically held at a logic

1 (mark) when no data is being transmitted, and is held “Off” for a brief

interval after an “On” to “Off” transition on the RTS line to allow the

transmission to complete.

Serial Port 1 or 2 – If in RS485 mode, this pin is RX Data –.

4RTS*

Tx Data +

7 Request To Send – Indicates serial port is ready to transmit data. Used

as hardware handshake with CTS for l o w level flow control.

Serial Port 1 or 2 – If in RS485 mode, this pin is TX Data +.

5TXD

Tx Data –

3Transmit Data – Serial port transmit data output is typically held to a

logic 1 when no data is being sent. T ypi cally, a logic 0 (On) must be

present on RTS, CTS, DSR, and DTR before data can be transmitted on

this line.

Serial Port 1 or 2 – If in RS485 mode, this pin is TX Data –.

6CTS*

Rx Data +

8Clear To Send – Indicator to the serial port that external serial

communication device is ready to receive data. Used as hardware

handshake with RTS for low level flo w control.

Serial Port 1 or 2 – If in RS485 mode, this pin is RX Data +.

7 DTR* 4 Data Terminal Ready – Indicates serial po rt is powered, initialized, and

ready. Used as hardware handshake with DSR for overall readiness to

communicate.

8 RI* 9 Ring Indicator – Indicator to serial port that external modem is detecting

a ring condition. Used by software to initiate operations to answer and

open the communications channel.

9GND 5 Digital Ground

10 KEY/NC NC Key Pin/Not connected

Notes: The shaded area denotes power or ground. The signals marked with * indicate active low.

Table 3-13. Serial 3 & 4 Interface Pins/Signals (J13, J14)

Pin # Signal DB9 # Description

1DCD* 1

Data Carrier Detect – Indicator to serial port that external modem is