HP LQH-HW 3ULQWHUV manual RS-232 And RS-422 Serial Interfaces

Chapter 14 RS-232 And RS-422 Serial Interfaces

RS-232 And RS-422 Serial Interfaces

Note	The RS-232 and RS-422 serial interface circuit characteristics are
	compatible with the Electronic Industry Association Specifications
	EIA®-232-E and EIA-422-B.

The RS-232 and RS-422 serial interfaces enable the printer to operate with bit serial devices that are compatible with an RS-232 controller. The input serial data transfer rate (in baud) is selectable from the printer operator panel. Baud rates of 600, 1200, 2400, 4800, 9600, 19,200, and 38,400 are available for RS-232 and RS-422.

The input format consists of a single start bit, 7 or 8 data bits, and one or two stop bits. The number of data bits is determined by printer configuration. The data bits are interpreted with the least significant bit first. Parity checking is determined by printer configuration options selected from the operator panel.

The printer interface uses a first-in/first-out buffer. The asynchronous interface accepts data as it is provided by the host. The length of the data cable from the host computer to the printer must not exceed 50 feet (15 meters) for RS-232 or 4000 feet (1220 meters) for RS-422. (A copper conductor, twisted-pair telephone cable with a shunt capacitance of 16 pF/ foot [52.5 pF/meter] terminated in a 100 ohm resistive load must be used for the RS-422.)

Table 17. RS-232 Serial Interface Connector Pin Assignments

Input Signals		Output Signals		Miscellaneous
Signal	Pin	Signal	Pin	Signal	Pin
Receive Data (RD)	3	Transmit Data (TD)	2	Chassis Ground	1
Clear To Send (CTS)	5	Request To Send (RTS)	4	Signal Ground	7
Data Set Ready (DSR)	6	Data Terminal Ready (DTR)	20
Data Carrier Detect (DCD)	8

Table 18. RS-422 Serial Interface Connector Pin Assignments

Input Signals		Output Signals		Miscellaneous
Signal	Pin	Signal	Pin	Signal	Pin
- Receive Data (-RD)	15	- Transmit Data (-TD)	19	Chassis Ground	1
+ Receive Data (+RD)	17	+ Transmit Data (+TD)	25	Signal Ground	7

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