Ampro LittleBoard 800, Reference Manual

Page: 49 / 96

Chapter 3 Hardware
LittleBoard 800 Reference Manual 43
Pin # Pin #
DB9 Signal Description
16 8 CTS2*
RX2+
Clear To Send 2 – Indicates external serial communications device is
ready to receive data. Used as hardware handshake with RTS2 for low
level flow control.
RX2+ – If in RS485 or RS422 mode, this pin is Receive Data 2 -.
17 4 DTR2* Data Terminal Ready 2 – Indicates Serial port 1 is powered, initialized,
and ready. Used as hardware handshake with DSR2 for overall readiness
to communicate.
18 9 NC Not Connected (Ring Indicator 2)
19 5 GND Ground
20 NC NC Not connected
Notes: The shaded area denotes power or ground. Signals are listed in the table with RS232 first,
followed by RS485/RS422.
Table 3-15. Serial B Interface Pin/Signal Descriptions (J12)
Pin # Pin #
DB9 Signal Description
1 1
(COM3)
DCD3* Data Carrier Detect 3 – Indicates external serial communications device
is detecting a carrier signal (i.e., a communication channel is currently
open). In direct connect environments, this input will be driven by DTR3
as part of the DTR/DSR handshake.
2 6 DSR3* Data Set Ready 3 – Indicates external serial communications device is
powered, initialized, and ready. Used as hardware handshake with DTR3
for overall readiness to communicate.
3 2 RXD3
RX3-
Receive Data 3 – Serial port 3 receive data in
RX3- – If in RS485 or RS422 mode, this pin is Receive Data 3 -.
4 7 RTS3*
TX3+
Request To Send 3 – Indicates Serial port 3 is ready to transmit data.
Used as hardware handshake with CTS3 for low level flow control.
TX3+ – If in RS485 or RS422 mode, this pin is Transmit Data 3 +.
5 3 TXD3
TX3-
Transmit Data 3 – Serial port 3 transmit data out
TX3- – If in RS485 or RS422 mode, this pin is Transmit Data 3 -.
6 8 CTS3*
RX3+
Clear To Send 3 – Indicates external serial communications device is
ready to receive data. Used as hardware handshake with RTS3 for low
level flow control.
RX3+ – If in RS485 or RS422 mode, this pin is Receive Data 3 -.
7 4 DTR3* Data Terminal Ready 3 – Indicates this Serial port is powered, initialized,
and ready. Used as hardware handshake with DSR3 for overall readiness
to communicate.
8 9 RI3* Ring Indicator 3 – Indicates external serial communications device is
detecting a ring condition. Used by software to initiate operations to
answer and open the communications channel.
9 5 GND Ground
10 NC KEY Not Connected