Black Box 202T User manual

CUSTOMER
SUPPORT
INFORMATION
Order toll-free in the U.S.: Call 877-877-BBOX (outside U.S. call 724-746-5500)
FREE technical support 24 hours a day, 7 days a week: Call 724-746-5500 or fax [phone]
Mailing address: Black Box Corporation, 1000 Park Drive, Lawrence, PA 15055-1018
Web site: www.blackbox.com • E-mail: [email protected]
MAY 2001
MD845A-R2
Modem 202T

1
FCC AND IC RFI INFORMATION
FEDERAL COMMUNICATIONS COMMISSION
AND
INDUSTRY CANADA
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 la classe A prescrites dans le Règlement sur le
brouillage radioélectrique publié par Industrie Canada.

2
MODEM 202T
FCC REQUIREMENTS FOR
TELEPHONE-LINE EQUIPMENT
1. The Federal Communications Commission (FCC) has established rules which
permit this device to be directly connected to the telephone network with
standardized jacks. This equipment is designed to operate only on dedicated
phone lines or wires. Do not connect to dial-up lines, coin lines, party lines, or
lines with dial tones.
2. If this device is malfunctioning, it may also be causing harm to the telephone
network; this device should be disconnected until the source of the problem
can be determined and until the repair has been made. If this is not done, the
telephone company may temporarily disconnect service.
3. If you have problems with your telephone equipment after installing this
device, disconnect this device from the line to see if it is causing the problem.
If it is, contact your supplier or an authorized agent.
4. The telephone company may make changes in its technical operations and
procedures. If any such changes affect the compatibility or use of this device,
the telephone company is required to give adequate notice of the changes.
5. If the telephone company requests information on what equipment is
connected to their lines, inform them of:
a. The telephone number that this unit is connected to.
b. The FCC registration number.
Item (b) can be found on the unit’s FCC label.
6. In the event of an equipment malfunction, all repairs should be performed by
your supplier or an authorized agent. It is the responsibility of users requiring
service to report the need for service to the supplier or to an authorized
agent.

3
CERTIFICATION NOTICE FOR EQUIPMENT USED IN CANADA
CERTIFICATION NOTICE FOR
EQUIPMENT USED IN CANADA
The Industry Canada label identifies certified equipment. This certification means
that the equipment meets certain telecommunications-network protective,
operation, and safety requirements. Industry Canada does not guarantee the
equipment will operate to the user’s satisfaction.
Before installing this equipment, users should ensure that it is permissible to be
connected to the facilities of the local telecommunications company. The
equipment must also be installed using an acceptable method of connection. In
some cases, the company’s inside wiring associated with a single-line individual
service may be extended by means of a certified connector assembly (extension
cord). The customer should be aware that compliance with the above conditions
may not prevent degradation of service in some situations.
Repairs to certified equipment should be made by an authorized maintenance
facility—in this case, Black Box. Any repairs or alterations made by the user to this
equipment, or equipment malfunctions, may give the telecommunications
company cause to request the user to disconnect the equipment.
Users should ensure for their own protection that the electrical ground
connections of the power utility, telephone lines, and internal metallic water pipe
system, if present, are connected together. This precaution may be particularly
important in rural areas.
CAUTION:
Users should not attempt to make such connections themselves, but
should contact the appropriate electric inspection authority, or
electrician, as appropriate.

4
MODEM 202T
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.
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.

5
NOM STATEMENT
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.

6
MODEM 202T
TRADEMARKS USED IN THIS MANUAL
Any trademarks mentioned in this manual are acknowledged to be the property of the
trademark owners.

7
CONTENTS
Contents
Chapter Page
1. Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3. Modem Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.1 Full Duplex 4-Wire Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.2 Half-Duplex 2-Wire Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.3 Half-Duplex 4-Wire Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.4 Simplex or Bits Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.5 Default Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4. Making Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.1 Connections Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.2 Power Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.3 RS-232 Serial Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.4 Operating Mode Selection and Wiring . . . . . . . . . . . . . . . . . . . . . . . 15
5. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.1 Component Locator Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.2 Baud Rate Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5.3 Character Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
5.4 Handshake Lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
5.5 Self-Test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Appendix. Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
A.1 Calling Black Box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
A.2 Shipping and Packaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

8
MODEM 202T
1. Specifications
Range: Up to 20 miles on unloaded lines, depending upon line characteristics.
Unlimited on loaded lines.
Operating Frequency: 1200/2200 Hz (Bell 202 or 1300/2100 CCITT V.35) FSK
(Frequency Shift Key)
Data Rates: 300, 600, or 1200 baud half- or full duplex up to 1200 baud simplex
Handshake Modes: DataSense (DSCC) or RTS line
Enclosure: Standard NEMA 1; 18-gauge steel with mounting flanges
Temperature Tolerance: -4 to +158°F (-20 to +70°C)
Indicators: (4) LEDs: Data Out, Data In, Carrier, Power
Connectors: (2) terminal blocks, (1) DB9 female
Power required: Input: 11 to 18 volts DC at a minimum of 200 ma. External
wallmount power supply provided for 110 VAC nominal.
Size: 1.5"H x 5"W x 9"D (3.8 x 12.7 x 22.9 cm) over mounting flanges
Mounting: Hole pattern 1⁄4inch diameter located on rectangle 8.3 by 2.8 inches

9
CHAPTER 2: Introduction
2. Introduction
The Modem 202T is a Bell 202 (CCITT V.23 optional) voice-band, 1200-baud
modem. Use it on private, leased, un-switched telephone lines or any dedicated 2-
or 4-conductor wire (twisted or untwisted, shielded or unshielded). The Modem
has a range of up to 20 miles (32.2 km) on any ordinary wire pairs or unlimited on
“loaded” telephone company voice-grade (VG-6) leased lines.
The Modem 202T can operate without handshake lines using the proprietary
DataSense (DSCC) microprocessor firmware. This feature detects and buffers
incoming RS-232 data to allow the assertion and stabilization of the FSK carrier
before transmitting the buffered characters.
The nominal operating supply voltage for the Modem 202T is 12 VDC via a
2-conductor screw terminal power connector.

10
MODEM 202T
3. Modem Configurations
3.1 Full Duplex 4-Wire Mode
To operate in full duplex, the Modem 202T must use a 4-wire connection and can
have only two units in a point-to-point connection. In full duplex, the Modem does
not use carrier control since both modems will have their carriers transmitting at
all times. No handshake signals are used by the modems, but the signals can be
asserted by the users’ equipment and fed back to the connecting equipment if
needed.
When operating, the Carrier Detect LED of both modems should be on at all
times. The carrier reflects the presence of the FSK frequency on the connecting
wires. The Data In LED (Yellow) and the Data Out LED (Green) of the modem
will follow the data at the RS-232 9-pin connector. The two modems are cross-
connected via the “2-wire” and “4-wire” connectors.
3.2 Half-Duplex 2-Wire Mode
The Modem 202T can operate in half-duplex 2-wire mode with one master and
one or more remote modems. The setup configuration is the same for the master
and remote modems. The user’s systems equipment must provide a timing delay
between a received message and a transmitted answer to allow the FSK carrier time
to switch directions.
The data flow control can be either DataSense (DSCC) or the RTS line from the
connected equipment.
In DSCC mode, the modem senses the characters from the user’s equipment, turns
on the FSK carrier, and then sends the buffered characters. All receiving modems
detect the carrier, then send the received data out the RS-232 port to the user’s
equipment. In DSCC mode, a minimum line turnaround delay of 40 milliseconds
is required.
With RTS control, the assertion of the RTS line by the user’s equipment tells the
modem to turn on the transmission carrier. Only the carrier at one modem can be
on at any time in a half-duplex system, or carrier collision will occur and no data
can be transferred. The minimum RTS timings are 20 milliseconds pre-transmit
delay, 60 milliseconds RTS to data, and zero milliseconds RTS off delay at the end
of the data. If you are adding the Modem 202T to an existing system with previous
models of Modem 202Ts, a minimum of 100 milliseconds RTS to data delay is
required.

11
CHAPTER 3: Modem Configurations
In a half-duplex system, the higher level equipment is responsible for recognizing
that the incoming data is valid and responds with return data. Either time delays
(DSCC mode) or handshake signals (RTS mode) must be provided to allow line
carrier turn around.
In a two-wire system, only the left connector marked “2-wire” is used to
interconnect all the modems in the system.
NOTE
These modems also use audio frequency tones and the connections to
the phone wires do not have a polarity.
The LEDs on a modem reflect the status of the lines at the 9-pin RS-232 connector.
When a modem is transmitting, the Data In (Yellow) LED will flash, and at the
remote modem the Carrier Detect (Amber) and Data Out (Green) LEDs will flash
as data is received.
3.3 Half-Duplex 4-Wire Mode
The Modem 202T will operate in half-duplex 4-wire mode with one master and
one or more remote modems.
The master’s carrier transmitter “4-wire” line must be connected to the remote’s
receiver line “2-wire” and vice versa. The master modem’s carrier is being
transmitted at all times so the remote’s carrier (Amber) LED will always be on. The
remote modem’s carrier is only transmitted when a remote modem is actively
sending data to the master.
No data flow control is needed at the master since its carrier is always on and ready
to transfer data. The data flow control at the remotes can be either DataSense or
the RTS line from the connected equipment.
In DSCC mode, the modem senses the RS-232 characters from your equipment,
turns on the FSK carrier, and then sends the characters. The master modem
detects the carrier, then the data, and and sends the received data out its RS-232
port to your equipment.
With RTS control, the assertion of the RTS line by your equipment tells the remote
modem to turn on the transmission carrier. Only one remote carrier can be on at
any time in a half duplex system or carrier collision will occur and no data can be
transferred. At a remote modem, your system must recognize that incoming data is
for the unit and must respond with data (DSCC) or RTS handshake line to provide
the correct timing delays to prevent carrier collisions. The minimum RTS timings

12
MODEM 202T
are 20 milliseconds pre-transmit delay, 60 milliseconds RTS to data, and zero
milliseconds RTS off delay at the end of the data. If adding Modem 202Ts to an
existing system with Modem 202Ts, a minimum of 100 milliseconds RTS to data
delay is required.
The Carrier Detect (Amber) LED on all remote modems in the system should be
on at all times. FSK data received at the remote will flash the Out (Green) LED
when data is sent out its RS-232 port. When a remote modem is transmitting, the
Data In (Yellow) LED will flash, and at the master modem the Carrier Detect
(Amber) and Data Out (Green) LEDs will flash.
3.4 Simplex or Bits Mode
In Bits mode, the Modem 202T sends data from a master to a remote(s) in one
direction only. In this mode, the modem is protocol- or format transparent and will
only operate in 2-wire mode. The data line is either a binary 1 or 0, producing a 1
or 0 at the receiving modem(s).
When connecting the modems to each other, use only the “2-Wire” connector
terminal block on all modems in the system.
With the Modems connected, the Carrier detect LED on the remote modem(s)
should be on at all times. The Carrier LED on the master will never be on. When
data is moving from the master to the remote modem(s), the Data In (Yellow) LED
on the master and the Data Out (Green) LED on the remote(s) will flash with the
data.
3.5 Default Configuration
The default configuration for the modem is:
Character Size: 10 bis/character (N, 8, 1)
Baud Rate: 1200
Carrier Frequency: Normal
Carrier On Select: DataSense
Modem Connection: 2-wire half-duplex

13
CHAPTER 4: Making Connections
4. Making Connections
The Modem 202T has four connection points. (See Figure 4-1.) On the left is the
DC power connection. The standard modem has a two-position terminal block
connector for use with the supplied wallmount power supply. The DB9 connector
is the RS-232 interface. To the right of the DB9 connector are two connections for
the carrier wire pairs marked “2-Wire” and “4-Wire.” These are two-position
removable terminal block connectors. In 2-wire mode, the left connector acts as
both the transmitter and receiver connector. In 4-wire mode, the unit sends audio
tones out the 4-wire connector (transmit) and receives tones on the 2-wire
connector (receive). All connections to the phone lines are through 600-ohm
transformers.
NOTE
When using the Modem 202T in a 4-wire configuration, the transmitter of
the master “4-wire” must be connected to the “2-wire” of the remote(s)
and all remote transmitter “4-wires” are wired in parallel to the master’s
receiver connector “2-wire.”
4.1 Connections Diagram
Figure 4-1. Connections.
LED S
• Power (P), red
• Carrier Detect (C), amber
• RS-232 In (I), yellow
• RS-232 Out (O), green
DC
Power In
Power
Connection
Serial
Interface Carrier
Connections
LEDs
RS-232 2-wire 4-wire Data
Out
Data
In Carrier
Detect
Power

14
MODEM 202T
4.2 Power Connector
The two-position screw terminal connector is left pin negative (-) and right pin
positive (+). DC negative is not connected to the chassis.
4.3 RS-232 Serial Connector
Table 4-1. RS-232 serial connector.
Pin Number Name Function
1 DCD* Received carrier detect out
2 TX RS-232 Data Out of Modem
3 RX RS-232 Data In to Modem
4 DTR Not connected in unit
5 Gnd Signal Ground
6 DSR* Data Set Ready (connected to CTS)
7 RTS* Ready to Send (transmit enable)
8 CTS Clear to Send [may be connected to
RTS or DCD] (connected to DSR)
9 RI Not connected in unit
*DCD via factory jumper to pin 1.

15
CHAPTER 4: Making Connections
4.4 Operating Mode Selection and Wiring
Table 4-2. Operating mode selection and wiring.
Wire Mode Use Connectors SW3 SW2-5 SW2-6 Notes
2 wire Half- 2 wire to 2 wire 2 wire OFF OFF One master with 1 or
Duplex parallel all units. more remotes.
Master or Carriers flash.
remote(s)
2 wire Simplex 2 wire is out. 2 wire ON ON Data flows from
(Bits) master to remote(s)
Master only. No carrier.
2 wire Simplex 2 wire is in. 2 wire ON OFF Data flows from
(Bits) master to remote(s)
Remote only. Carrier on.
4 wire Half- Cross wire 4 wire 4 wire ON ON One master with 1
Duplex to all remote 2 wire or more remotes.
Master and 2 wire from all
remote 4 wire.
4 wire Half- Same as 4-wire 4 wire ON OFF Remote carrier LED
Duplex Master. Cross wire. always on.
Remote
4 wire Full Cross connect 2 wire 4 wire OFF ON 2 Modem 202Ts only.
Duplex to 4 wire between Both carrier LEDs on.
both units.
NOTE
SW3 2-wire with SW2-5 off and SW2-6 on will enter self-test display.
SW3 4-wire with SW2-5 off and SW2-6 off is an invalid combination.

16
MODEM 202T
5. Operation
5.1 Component Locator Diagram
Figure 5-1. Component locator.
If the Modem 202T will be used with existing Modem 202Ts, you must set SW1 for
Modem 202T mode (SW1 set away from SW3) to maintain frequency compatibility.
JP1
SW2
ON OFF
SW3
JP3 6
1
2-wire
Power RS-232 Carrier Lines LEDs
4-wire
Standard
Carrier
Modem
Compatible
SW1

17
CHAPTER 5: Operation
NOTE
The default setting for SW2 is positions 1–5 OFF and position 6 ON.
If you need to field configure a Modem 202T, you will need the following
information.
1. Baud rate of the serial device you are connecting with (unless using simplex).
2. Character format (1 start bit + # data bits + parity + 1 stop bit). This must add
to 10 or 11 bits.
Set SW2-3 ON = 11 bits, or OFF = 10 bits.
3. Use of RTS line from your equipment to control the flow of data into and
between modems. If RTS use is unknown, set the unit for DSCC DataSense
mode.
Set SW2-4 OFF = DSCC DataSense ON = RTS
4. Either 1 wire pair (2-wire mode) or 2 wire pairs (4-wire mode). Set SW3.
5. Half or full duplex data transmission method, bi-directional or one-way data
flow (simplex). Set SW2-5 and SW2-6 using the information in Table 4-2.
NOTE
After changing any switches, remove DC power and reapply to
memorize the changes. Switches are only read during power on.
5.2 Baud Rate Selection
The Modem 202T will operate at 300, 600, and 1200 baud in a 10- or 11-bit word
format. The modem is parity transparent; however, it must know if there are 8 or 9
bits of data/parity. In Simplex mode, the Modem is baud-rate and protocol
transparent and the baud switches are ignored. The Baud rate is set using switches
SW2-1 and SW2-2.
Table 5-1. Selecting the baud rate.
Baud Rate SW2-1 SW2-2
*1200 OFF OFF
600 ON OFF
300 ON ON
Not Used OFF ON
*Default

18
MODEM 202T
5.3 Character Format
To find the character format of your equipment, take the number of data bits in a
character. If parity is used (odd, even, mark, space), add one (1). If parity is not
used, don’t add anything. Add two for one start bit and one stop bit. The result
must be 10 or 11. Use SW2-3 to set the length. SW2-3 is OFF for 10 bits, and ON for
11 bits. This switch is ignored in simplex mode.
5.4 Handshake Lines
If RTS handshaking mode is set, the Modem 202T needs the RTS asserted when it
is time to transmit data onto the FSK carrier from the equipment. Depending
upon how the modem is configured, it can provide DCD, CTS, and DSR signaling
back to your equipment. JP3 is used to configure these lines.
If these lines are needed, note that:
• Shorting pins 1 and 2 will pull DCD (pin 1) logic high at the DB9 connector.
• Shorting pins 2 and 3 will pass carrier status to DCD (pin 1) at the DB9
connector.
• Shorting pins 4 and 5 will route incoming RTS (pin 7) to outgoing CTS (pin
8) and outgoing DSR (pin 6) at the DB9 connector.
• Shorting pins 5 and 6 will route DSR and CTS to pin 1. Also, shorting pins 2
and 3 will connect DCD (pin 1) to outgoing CTS (pin 8) and outgoing DSR
(pin 6) at the DB9 connector.
NOTE
DSR (pin 6) and CTS (pin 8) are always connected to DTR.
5.5 Self-Test
The Modem 202T has a built-in test mode that verifies whether the processor is
operating normally. It displays the operating configuration as set by the SW2
switches and the 2-/4-wire mode switch SW3.
To conduct the self-test:
1. Remove DC power.
2. Remove the cover.

19
CHAPTER 5: Operation
3. Temporarily short together the JP1 header pins 1 and 3 and re-apply DC
power.
4. A repeating sequence will occur. First, the Green LED (O) will flash, followed
by seven (7) flashes of the Amber LED (“C”).
5. The Green LED is the processor outputting the switch setup and operating
mode as serial data at 1200 baud, formatted as 8 data, no parity, 1 stop bit. To
view this data, connect a PC to the 9-pin D sub connector using 3 wires (pins
2, 3, 5) or a straight-through serial cable. Start a communications program
such as Procomm or HyperTerminal set to 1200, n, 8, 1. The next set of
Green flashes will put the modem configuration on the PC display.
6. The Amber LED flashes are the 6 positions of SW2 and the position of SW3. A
short flash means the switch is in the OFF position. A long flash means it is in
the ON position. For SW3, OFF is towards SW1 (4-wire) and ON is away from
SW1 (2-wire).
7. Compare the ON/OFF pattern to the setup tables for baud, handshake, # of
bits, and user operating mode.
8. Remove DC power and any JP1 connections.
9. Reapply DC power to enter your selected operating setup mode.