Black Box TTL User manual

OCTOBER 1999
IC156A-R2
TTL Converter
CUSTOMER SUPPORT INFORMATION
Order toll-free in the U.S. 24 hours, 7 A.M. Monday to midnight Friday: 877-877-BBOX
FREE technical support, 24 hours a day, 7 days a week: Call 724-746-5500 or fax [phone]
Mail order: Black Box Corporation, 1000 Park Drive, Lawrence, PA 15055-1018
Web site: www.blackbox.com • E-mail: [email protected]
TTL Converter

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TTL CONVERTER
FEDERAL COMMUNICATIONS COMMISSION
AND
CANADIAN DEPARTMENT OF COMMUNICATIONS
RADIO FREQUENCY INTERFERENCE STATEMENTS
This equipment generates, uses, and can radiate radio frequency energy and if
not installed and used properly, that is, in strict accordance with the
manufacturer’s instructions, may cause interference to radio communication. It
has been tested and found to comply with the limits for a Class A computing
device in accordance with the specifications in Subpart J of Part 15 of FCC rules,
which are designed to provide reasonable protection against such interference
when the equipment is operated in a commercial environment. Operation of
this equipment in a residential area is likely to cause interference, in which case
the user at his own expense will be required to take whatever measures may be
necessary to correct the interference.
Changes or modifications not expressly approved by the party responsible for
compliance could void the user’s authority to operate the equipment.
This digital apparatus does not exceed the Class A limits for radio noise emission from
digital apparatus set out in the Radio Interference Regulation of Industry Canada.
Le présent appareil numérique n’émet pas de bruits radioélectriques dépassant les limites
applicables aux appareils numériques de classe A prescrites dans le Règlement sur le
brouillage radioélectrique publié par Industrie Canada.
The CE symbol on your equipment indicates that it complies with the
Electromagnetic Compatibility (EMC) directive and the Low Voltage Directive
(LVD) of the Union European (EU).

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TTL CONVERTER
NORMAS OFICIALES MEXICANAS (NOM)
ELECTRICAL SAFETY STATEMENT
INSTRUCCIONES DE SEGURIDAD
1. Todas las instrucciones de seguridad y operación deberán ser leídas antes
de que el aparato eléctrico sea operado.
2. Las instrucciones de seguridad y operación deberán ser guardadas para
referencia futura.
3. Todas las advertencias en el aparato eléctrico y en sus instrucciones de
operación deben ser respetadas.
4. Todas las instrucciones de operación y uso deben ser seguidas.
5. El aparato eléctrico no deberá ser usado cerca del agua—por ejemplo,
cerca de la tina de baño, lavabo, sótano mojado o cerca de una alberca,
etc..
6. El aparato eléctrico debe ser usado únicamente con carritos o pedestales
que sean recomendados por el fabricante.
7. El aparato eléctrico debe ser montado a la pared o al techo sólo como sea
recomendado por el fabricante.
8. Servicio—El usuario no debe intentar dar servicio al equipo eléctrico más
allá a lo descrito en las instrucciones de operación. Todo otro servicio
deberá ser referido a personal de servicio calificado.
9. El aparato eléctrico debe ser situado de tal manera que su posición no
interfiera su uso. La colocación del aparato eléctrico sobre una cama,
sofá, alfombra o superficie similar puede bloquea la ventilación, no se
debe colocar en libreros o gabinetes que impidan el flujo de aire por los
orificios de ventilación.

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TTL CONVERTER
10. El equipo eléctrico deber ser situado fuera del alcance de fuentes de calor
como radiadores, registros de calor, estufas u otros aparatos (incluyendo
amplificadores) que producen calor.
11. El aparato eléctrico deberá ser connectado a una fuente de poder sólo del
tipo descrito en el instructivo de operación, o como se indique en el
aparato.
12. Precaución debe ser tomada de tal manera que la tierra fisica y la
polarización del equipo no sea eliminada.
13. Los cables de la fuente de poder deben ser guiados de tal manera que no
sean pisados ni pellizcados por objetos colocados sobre o contra ellos,
poniendo particular atención a los contactos y receptáculos donde salen
del aparato.
14. El equipo eléctrico debe ser limpiado únicamente de acuerdo a las
recomendaciones del fabricante.
15. En caso de existir, una antena externa deberá ser localizada lejos de las
lineas de energia.
16. El cable de corriente deberá ser desconectado del cuando el equipo no
sea usado por un largo periodo de tiempo.
17. Cuidado debe ser tomado de tal manera que objectos liquidos no sean
derramados sobre la cubierta u orificios de ventilación.
18. Servicio por personal calificado deberá ser provisto cuando:
A: El cable de poder o el contacto ha sido dañado; u
B: Objectos han caído o líquido ha sido derramado dentro del
aparato; o
C: El aparato ha sido expuesto a la lluvia; o
D: El aparato parece no operar normalmente o muestra un cambio en
su desempeño; o
E: El aparato ha sido tirado o su cubierta ha sido dañada.

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TTL CONVERTER
TRADEMARKS
The trademarks mentioned in this manual are the sole
property of their owners.

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TTL CONVERTER
Contents
Chapter Page
1. Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3. Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.1 Default TTL Logic Levels . . . . . . . . . . . . . . . . . . 9
3.2 Opening the Case. . . . . . . . . . . . . . . . . . . . . . . . . 10
3.3 Changing the Jumper Straps . . . . . . . . . . . . . . . . 12
Jumper Switches JP1 and JP2. . . . . . . . . . . . . . . . 13
4. Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Connecting the TTL Converter . . . . . . . . . . . . . . . . 17
Appendix A: Interface Pin Assignments. . . . . . . . . . . . 18
Appendix B: Block Diagram . . . . . . . . . . . . . . . . . . . . . 19

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TTL CONVERTER
1. Specifications
Transmission Format—Asynchronous
Data Rate—0 to 230 kbps
Interface—Serial TTL (DTE) or serial RS-232
(DCE)
Connectors—(1) DB25 female for RS-232 interface,
(1) DB25 male for TTL interface
Control Signals Supported—CD, DTR, DSR, CTS,
and RTS, passed directly through
Signal Inversion—Data signals and control signals
can be independently configured for “inverting”
or “non-inverting” using internal jumpering
Power Supply—None required; draws all necessary
operating power from RS-232 and TTL data and
control signals
Temperature—32 to 122 °F (0 to 50 °C)
Size—2.2"H x 2.1"W x 0.7"D (5.6 x 5.3 x 1.8 cm)
Weight—2 oz. (0.1 kg)

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TTL CONVERTER
2. Introduction
2.1 Description
The TTL Converter lets an asynchronous RS-232 device
communicate bi-directionally with an asynchronous TTL
device. Supporting data rates up to 230 kbps, the
Converter passes data (TD, RD) plus five control signals
(CD, DTR, DSR, CTS, and RTS). In addition, the
Converter allows data and control signals to be
independently jumper-selected as “inverting” or “non-
inverting.”
The TTL Converter has a serial RS-232 interface
(DCE) and a serial TTL interface (DTE). The RS-232
interface is presented on a DB25 female connector,
while the TTL interface is presented on a DB25 male
connector. Since it derives power from the data and
control signals, the Converter requires no AC power or
batteries for operation.
2.2 Features
• Bi-directional, asynchronous data conversion
between RS-232 and TTL

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TTL CONVERTER
• Supports data rates to 230 kbps
• Connects an RS-232 DTE to a TTL DCE
• Passes TD & RD plus five control signals: CD,
DTR, DSR, CTS & RTS
• Data and control signals independently selectable
for inverting/non-inverting
• Interface powered—no AC required
• RS-232 interface is a DB25 female, TTL interface is
a DB25 male

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TTL CONVERTER
3. Configuration
The TTL Converter is very easy to use. Most
applications require no configuration. Just plug it in
and go! However, some TTL circuitry requires data
and/or control signals to be inverted (opposite) from
their normal conditions. Please read the section below
to determine if the default settings will work for you.
3.1 Default TTL Logic Levels
Systems represents data signals by alternating between
“mark” (binary “1”) and space (binary “0”) conditions.
TTL (Transistor-Transistor Logic) circuitry normally a
represents a “mark” as a voltage between 2.4 and 5.0
Volts, and a “space” as a voltage between 0.0 and 0.4
Volts. By contrast, TTL control signals (RTS, CTS, DSR,
DCD and DTR) are either “active” (between 0.0 and 0.4
Volts), or “inactive” (between 2.4 and 5.0 Volts).
Table 3-1 summarizes the above information.
Table 3-1. Default TTL Signal Levels.
Signal Level Data Signals Control Signals
0 to 0.4 volts space active
2.4 to 5.0 volts mark inactive

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TTL CONVERTER
Table 3-1, shows the default configuration of the
Converter. In most cases no modification is required.
However, if your TTL circuitry requires inverted signals
for either the data or control signals, you must change
the settings of one or two jumper switches. To change
the jumper settings, you must open the case. Please
follow the instructions below.
3.2 Opening the Case
Remember that, for most applications, you will not have
to change the jumper settings. Unless the default
settings won’t work for your application, skip the rest of
this chapter and go on to Chapter 4.
The JP1 and JP2 jumpers on the TTL Converter are
located on the PC board. To open the case, insert a
small flathead screw driver or similar tool between the
DB25 female connector and the lip of the case as shown
in Figure 3-1.

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TTL CONVERTER
Figure 3-1. Using a small screwdriver to open the TTL Converter case.
Then gently twist the screwdriver to pop the case open
as shown in Figure 3-2. Be careful not to damage the
case or connector as you twist the screwdriver.
Figure 3-2. Using a small screwdriver to open the TTL Converter case.

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TTL CONVERTER
3.3 Changing the Jumper Straps
Once you have opened the case of the TTL Converter,
you will see two jumper straps located on the top side of
the PC board (see Figure 3-3).
Figure 3-3. Location of the TTL Converter’s Jumper Straps.
To change the jumper-strap settings, simply remove
the jumpers and replace them on the jumper posts as
described below.
TTL Side (Male) RS-232 Side (Female)
JP1 JP2

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TTL CONVERTER
J UMPER
S WITCHES JP1 AND JP2
Use jumper switches JP1 and JP2 to control the logic
state of the data and/or control signals. In most cases, you
will NOT have to modify these settings. Consult the user
manual of the TTL device or the device’s manufacturer
before changing the settings on JP1 and JP2.
Non-Inverted Data and Control Signals (Default Setting)
Position JP1 and JP2 vertically on the jumper posts to
select non-inverted data and control signals (default
setting). Figure 3-4 shows the relative signal levels.
Figure 3-4. Non-Inverted Data and Control Signal Jumpers.
JP1
TTL Side RS-232 Side
JP2

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TTL CONVERTER
Table 3-2. Non-Inverted Data and Control.
Signal Level Data Signals Control Signals
0 to 0.4 volts space active
2.4 to 5.0 volts mark inactive
Inverted Data and Control Signals
Position JP1 and JP2 horizontally on the jumper posts to
select inverted data and control signals. Figure 3-5 shows
the position of the jumpers on the PC board. Table 3-3
shows the relative signal levels.
Figure 3-5. Inverted Data and Control-Signal Jumpers.
Table 3-3. Inverted Data and Control-Signal Jumpers.
Signal Level Data Signals Control Signals
0 to 0.4 volts mark inactive
2.4 to 5.0 volts space active
JP1
TTL Side RS-232 Side
JP2

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TTL CONVERTER
Inverted Data and Non-Inverted Control Signals
Position JP1 horizontally on the jumper posts and
remove JP2 to select inverted data and non-inverted
control signals. Figure 3-6 shows the position of the
jumpers on the PC board. Table 3-4 shows the relative
signal levels.
Figure 3-6. Inverted Data and Non-Inverted Control-Signal Jumpers.
Table 3-4. Inverted Data and Non-Inverted Control-Signal Jumpers.
Signal Level Data Signals Control Signals
0 to 0.4 volts mark active
2.4 to 5.0 volts space inactive
JP1
TTL Side RS-232 Side
JP2

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TTL CONVERTER
Inverted Control and Non-Inverted Data Signals
Position JP2 horizontally on the bottom jumper posts to
select inverted control and non-invert data signals.
Figure 3-7 shows the position of the jumpers on the PC
board. Table 3-5 shows the relative signal levels.
Figure 3-7. Inverted Control and Non-Inverted Data Signal Jumpers.
Table 3-5. Inverted Control and Non-Inverted Data Signal Jumpers.
Signal Level Data Signals Control Signals
0 to 0.4 volts space inactive
2.4 to 5.0 volts mark active
JP1
TTL Side RS-232 Side
JP2

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TTL CONVERTER
4. Installation
The TTL Converter is very simple to install. Just plug it
in like a normal cable and you’re ready to go.
NOTE
The TTL Converter uses a DB25 female connector on the
RS-232 interface and a DB25 male connector on the TTL
Interface.
C ONNECTING THE TTL C ONVERTER
Connect the 25-pin male port (TTL side) directly to a
TTL DCE device. Connect the 25-pin female port
(RS-232 side) of the TTL Converter to an RS-232 DTE
device using a straight-through cable of the shortest
possible length (less than 50 feet). Figure 4-1 shows the
typical application of the TTL Converter.
Figure 4-1. Connecting the TTL Converter.
RS-232 DTE
TTL DCE
TTL Converter

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TTL CONVERTER
Appendix A: Interface Pin
Assignments
Figure A-1. RS-232 Interface.
Figure A-2. TTL Interface.
1-(FG) Frame Ground
2-(TD) Transmit Data
3-(RD) Receive Data
4-(RTS) Request to Send
5-(CTS) Clear to Send
6-(DSR) Data Set Ready
7-(SG) Signal Ground
8-(DCD) Data Carrier Detect
9-(DCV+) Aux Power
Data Terminal Ready (DTR)-20
Data Terminal Ready (DTR)-20
1-(FG) Frame Ground
2-(TD) Transmit Data
3-(RD) Receive Data
4-(RTS) Request to Send
5-(CTS) Clear to Send
6-(DSR) Data Set Ready
7-(SG) Signal Ground
8-(DCD) Data Carrier Detect
9-(DCV+) Aux Power

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TTL CONVERTER
Appendix B: Block Diagram
SIGNAL GROUND
CD
DTR
DSR
CTS RTS
RD
TD
FRAME GROUND
SIGNAL GROUND
CD
DTR
DSR
CTS
RTS
RD
TD
FRAME GROUND
>
> > >
> > >
1 2 3 4 5 6 7 20 8
1 2 3 4 5 6 7 20 8
DCE
TTL
DEVICE
DTE
RS-232
DEVICE
RS-232 to TTL CONVERTER
V+ >
DTR >
CTS >
RD >
CD >
DSR >
RTS >
TD >
2 4 6 8
3 5 20 9
INVERTING/ NON-INVERTING SWITCH
POWER
SUPPLY
+V
GROUND