Document No. 422CFCR3498 - pg. 1/2
B&B Electronics February 1996 -- Revised September 1998
This product designed and manufactured in USA of domestic and imported parts by
Reversed Four Channel RS-232 to RS-422 Converter
CE
CE
Model 422CFCR
The RS-232 to RS-422 Converter converts unbalanced RS-232 signals to
balanced RS-422 signals. The RS-422 Standard uses a balanced voltage digital
interface to allow communications of 90k bits per second on cable lengths of 4000
feet. Ten receivers can be connected to any one driver for use in multi-drop systems.
Interconnection of the converter with another RS-422 device:
1.
The polarity of the two RS-422 lines must be correct. With no data being sent, the RS232 line should be
negative and the RS-422 A terminal should be negative with respect to the B terminal. If your equipment uses a + and -
naming scheme, in most cases, the A line will be connected to the "-", and the B line will be connected to the "+".
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 rates (more than 200k bits per second) it is recommended that the wires be terminated
with a resistor at the receive end. The twisted pair usually used has an impedance of about 100 ohms, therefore a 100
ohm resistor is normally used for the termination. In no case should the resistive termination be less than 90 ohms.
4.
The RS-422 driver has the ability to drive ten RS-422 receivers connected in parallel. A system of multiple
receivers may require some experimentation with location and size of termination resistors, line lengths, grounding, etc.
5.
The RS-422 Standard recommends that Protective Ground (pin 1) be connected to a good "green wire" ground.
This may already be connected in your RS-232 equipment. Protective Ground and Signal Ground should be connected
through to each end of the system and be connected to each other using a 100 ohm 1/2-watt resistor at one end only. If
a shielded, twisted pair is used, the shield should be connected to Protective Ground.
DECLARATION OF CONFORMITY
Manufacturer's Name:
B&B Electronics Manufacturing Company
Manufacturer's Address:
P.O. Box 1040
707 Dayton Road
Ottawa, IL 61350 USA
Model Numbers:
422CFCR
Description:
Reversed Four Channel RS-232 to 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)
Paul A. Boeing, Director of Engineering
PDF 
ZIP