Documentation Number 232TTL3401 - pg. 1/2
1993 B&B Electronics Revised September 2001
This product designed and manufactured in USA of domestic and imported parts by
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:
232TTL
Description:
Four-Channel RS-232 to TTL Converter
Type:
Light industrial ITE equipment
Application of Council Directive:
89/336/EEC
Standards: EN
50082-1:1998
EN 50082-1:1992 IEC 801 (-3, -4)
EN 61000 (-4-2, -4-3, -4-4, -4-6)
Michael J. Fahrion, Director of Engineering
Four-Channel RS-232 to TTL Converter
CE
Model 232TTL
Description
The 232TTL converts RS-232 to TTL levels. Two channels are
used to convert from RS-232 to 0 to +5 VDC TTL signals and two
channels are used to convert from 0 to +5 VDC TTL signals to RS-232.
This converter supports RD, TD, RTS, and CTS. The DB25P male
connector (DCE) is for the RS-232 side. The DB25S female connector is
for the TTL side.
The pins used are:
DB25P Male
DB25S Female
RS-232
TTL
Pin Function Pin
2
(input)............................. TD ...........................9
(output)
3
(output) .......................... RD ..........................14
(input)
4
(input)............................ RTS .........................16
(output)
5
(output) ......................... CTS .........................23
(input)
Pin 7 is signal ground for both connectors. The unit can work at baud rates up to 115K baud. On the RS-232 side,
pins 8 (DCD), 20 (DTR), and 6 (DSR) are connected to open pads, if you would rather use these instead of the given RS-
232 lines. Another feature is that the TTL and RS-232 pins can be changed by connecting wires from the pins you want to
pads that have been provided. The unit needs a +12VDC power supply (100 mA approx.). A power supply is available
from B&B.
It is important that TTL logic, and only TTL logic (0 to +5 VDC) is used for the TTL side of the converter. The
maximum sinking current for one TTL output is 3.2 mA. The maximum source current for one TTL is 1 mA. Signal levels
are inverted by the converter. Please refer to table below.
POLARITY
TTL Input
RS-232 Output
Units
low
positive
volts
high
negative
volts
TTL Output
RS-232 Input
Units
low
positive
volts
high
negative
volts
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