Ampro Corporation Littleboard 550 manual CTS2, DTR2, DCD3, DSR3, RXD3, RTS3, TXD3, CTS3, DTR3

Chapter 3				Hardware
	Pin #	Pin #	Signal	Description
		DB9
	16	8	CTS2*	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+	RX2+ – If in RS485 or RS422 mode, this pin is Receive Data 2 -.
	17	4	DTR2*	Data Terminal Ready 2 – Indicates Serial port 2 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 following order RS232 and RS485/RS422.

Table 3-15. Serial B Interface Pin/Signal Descriptions (J13)

Pin #	Pin #	Signal	Description
	DB9
1	1	DCD3*	Data Carrier Detect 3 – Indicates external serial communications device
	(COM3)		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	Receive Data 3 – Serial port 3 receive data in
		RX3-	RX3- – If in RS485 or RS422 mode, this pin is Receive Data 3 -.
4	7	RTS3*	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+	TX3+ – If in RS485 or RS422 mode, this pin is Transmit Data 3 +.
5	3	TXD3	Transmit Data 3 – Serial port 3 transmit data out
		TX3-	TX3- – If in RS485 or RS422 mode, this pin is Transmit Data 3 -.
6	8	CTS3*	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+	RX3+ – If in RS485 or RS422 mode, this pin is Receive Data 3 -.
7	4	DTR3*	Data Terminal Ready 3 – Indicates Serial port 3 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/	Key
		NC	Not connected

LittleBoard 550 Reference Manual 45