ADLINK CoreModule 745 - Manual (Page 30)

Chapter 3 Hardware
24 Reference Manual CoreModule 745
Table 3-4 defines the pins and corresponding signals for serial ports 1 and 2 headers (J3 and J4), which each
consist of 10 pins, 2 rows, odd/even sequence (1, 2), and 0.079" (2mm) pitch.
Note: The shaded table cell denotes power or ground. The * symbol indicates the signal is Active Low.
Table 3-4. Serial Ports 1 & 2 Interface Pin Signal Descriptions (J3 and J4)
Pin # Signal DB9 # Description
1 DCD* 1 Data Carrier Detect – Indicates external serial device is detecting a
carrier signal (i.e., a communication channel is currently open). In direct
connect environments, this input is driven by DTR as part of the
DTR/DSR handshake.
2 DSR* 6 Data Set Ready – Indicates external serial device is powered, initialized,
and ready. Used as hardware handshake with DTR for overall readiness.
3 RXD
Rx Data –
2 Receive 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 RS-485 mode, this pin is Rx Data Negative.
4 RTS*
Tx Data +
7 Request To Send – Indicates serial port is ready to transmit data. Used as
hardware handshake with CTS for low level flow control.
Serial Port 1 or 2 – If in RS-485 mode, this pin is Tx Data Positive.
5 TXD
Tx Data –
3 Transmit Data – Serial port transmit data output is typically held to a
logic 1 when no data is being sent. Typically, 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 RS-485 mode, this pin is Tx Data Negative.
6 CTS*
Rx Data +
8 Clear To Send – Indicates external serial device is ready to receive data.
Used as hardware handshake with RTS for low level flow control.
Serial Port 1 or 2 – If in RS-485 mode, this pin is Rx Data Positive.
7 DTR* 4 Data Terminal Ready – Indicates serial port is powered, initialized, and
ready. Used as hardware handshake with DSR for overall readiness.
8 RI* 9 Ring Indicator – Indicates external serial device is detecting a ring
condition. Used by software to initiate operations to answer and open the
communications channel.
9 GND 5 Ground
10 Key/NC NC Key Pin/Not connected