Specifications

Chapter 3 Hardware
ReadyBoard 800 Reference Manual 37
Serial A Interface (J15A/B)
Table 3-8. Serial A (Serial 1) Interface Pin/Signal Descriptions (J15A)
Pin
#
Signal Description
1 DCD1* Data Carrier Detect 1 – 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 DTR1 as part of the DTR/DSR handshake.
2 RXD1 Receive Data 1 – Serial port 1 receive data in
3 TXD1 Transmit Data 1 – Serial port 1 transmit data out
4DTR1*
Data Terminal Ready 1 – Indicates serial port is powered, initialized, and ready.
Used as hardware handshake with DSR1 for overall readiness to communicate.
5 GND Ground
6DSR1*
Data Set Ready 1 – Indicates external serial device is powered, initialized, and
ready. Used as hardware handshake with DTR1 for overall readiness.
7 RTS1* Request To Send 1 – Indicates serial port is ready to transmit data. Used as
hardware handshake with CTS1 for low level flow control.
8 CTS1* Clear To Send 1 – Indicates external serial device is ready to receive data. Used as
hardware handshake with RTS1 for low level flow control.
9RI1*
Ring Indicator 1 – Indicates external serial device is detecting a ring condition.
Software initiates operation to answer and open the communications channel.
Notes: The shaded area denotes power or ground. The signals marked with * = Negative true logic.
Table 3-9. Serial A (Serial 2) Interface Pin/Signal Descriptions (J15B)
Pin # Signal Description
1 DCD2* Data Carrier Detect 2 – 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 DTR2 as part of the DTR/DSR handshake.
2 RXD2 Receive Data 2 – Serial port receive data in.
3 TXD2 Transmit Data 2 – Serial port transmit data out.
4 DTR2* Data Terminal Ready 2 – Indicates serial port is powered, initialized, and ready.
Used as hardware handshake with DSR2 for overall readiness to communicate.
5 GND Ground
6 DSR2* Data Set Ready 2 – Indicates external serial device is powered, initialized, and
ready. Used as hardware handshake with DTR2 for overall readiness.
7RTS2*
Request To Send 2 – Indicates serial port is ready to transmit data. Used as
hardware handshake with CTS2 for low level flow control.
8 CTS2* Clear To Send 2 – Indicates external serial device is ready to receive data. Used as
hardware handshake with RTS2 for low level flow control.
9 RI2* Ring Indicator 2 – Indicates external serial device is detecting a ring condition.
Software initiates operation to answer and open the communications channel.
Notes: The shaded area denotes power or ground. The signals marked with * = Negative true logic.