B&B Electronics 422LP25N Datasheet

422LP25N-1506ds - 1/2

Model: 422LP25N

Port-powered RS-232 to RS-422 Converter

with DB-25 Connectors

This RS-232 to RS-422 converter converts unbalanced RS-232 signals to balanced RS-422 signals. Power is derived from the transmit data line (pin 2) and the handshake control lines (pins 4, 5, 6, 8, and 20). The converter can derive power from these lines when they are in the positive or negative voltage state. This permits the converter to b e used in applications without any regard to software control of the handshake lines. If no handshak e lines are available and all power must be derived from the transmit data line, the converter c an drive limite d cable len gths. A guide for this condition would be to drive only several hundred feet of transmission li ne and not to term inate th e trans mission lin e with a resistor of less than 1000 Ohms. When more handshake lines are av ailable longer lengths of cable can be driven. This converter has been tested at 115.2k baud with 4000 feet of cable. For applications where handsh ake lines are not available and long cable runs are involve d, an external power suppl y can be connected to the female connector on th e RS-422 side of the converter on pins 12 (Gnd) and 25 (+12).

NOTE: When using an external supply, the supply should be connected only to specifically labeled power inputs (power jack, terminal block, etc.). Connecting an external power supply to the handshake lines may damage the unit. Contact technical support for more information on connecting an external power supply to the handshake lines.

The RS-232 port uses a male DB-25 type of connector with pins 2 (TD input) and 3 (RD output) supporte d. Signal Ground is pin 7 on both the RS-232 and RS-422 sides. Temperature range for this converter = 0 to 70 ºC.

Interconnection of the converter with another RS-422 device:

1. The polarity of the two RS-422 lines must be corr ect. With no data being sent, the RS-232 line should be negative and the RS-422 "A" pin 2 should be negative with respect to the "B" pin 14.

2. The wire recommended in the RS-422 Standard is number 24 AWG copper conductor, twisted- pair telephone cable with a shunt capacitance of 16 pF per foot.

3. For long runs and/or high data rates it is recommended that the wires be terminated with a resistor at the receive end. The twisted pair usually used h as a n im pe dan ce of about 10 0 ohms, ther efore a 100 ohm resistor is normally used for the termination. The RS-422 side of the converter requires more power as the transmission line is increased and as the termination resistor value is re duced, therefore it may be necessary to use a termination resistor that is larger than 100 ohms.

4. The RS-422 driver has the ability to drive 10 RS-422 receiv ers con nected i n par allel. A s ystem of multipl e receivers

may require some experimentation with location and size of termination resistors, line lengths, grounding, etc.

Manufacturer’s Name: B&B Electronics Manufacturing Company Manufacturer’s Address: P.O. Box 1040

707 Dayton Road

Model Numbers: 422LP25N Description: Port-powered RS-422 Converter Type: Light industrial ITE equipment Application of Council Directive: 89/336/EEC Standards: EN 50082-1 (IEC 801-2, IEC 801-3, IEC 801-4)

EN 50081-1 (EN 55022, IEC 1000-4-2) EN 61000 (-4-2, -4-3, -4-4, -4-5, -4-6, -4-8, -4-11) ENV 50204 EN 55024

DECLARATION OF CONFORMITY

Ottawa, IL 61350 USA

Robert M. Paratore, Director of Engineering

815-433-5100 Fax 433-5104 www.bb-elec.com orders@bb-elec.com support@bb-elec.com

PRODUCT INFORMATION B&B ELECTRONICS

+353 91 792444 Fax +353 91 792445

International Headquarters: 707 Dayton Road PO Box 1040 Ottawa, IL 61350 USA

European Headquarters: Westlink Commercial Park Oranmore Co. Galway Ireland

www.bb-europe.com orders@bb-europe.com support@bb-europe.com