Tandy DC-2212 User manual

IMPORTANT NOTE!
Your DC-2212 Intelligent Modem is factory preset with the AUTO
ANSWER switch in the OUT position. At power-up, this switch
position provides the "Auto-Dial Mode" which is the proper setting for
most software applications.
Under XENIX, however, this switch must be set to the IN position for
proper operation. (The IN position provides " true carrier detect. " )
Also note that on Xenix versions prior to 3.0, the unattended auto-dial
feature is not supported.

TERMS AND CONDITIONS OF SALE AND LICENSE OF RADIO SHACK COMPUTER EQUIPMENT AND SOFTWARE
PURCHASED FROM A RADIO SHACK COMPANY-OWNED COMPUTER CENTER. RETAIL STORE OR FROM A
RADIO SHACK FRAN C HISEE OR DEALER AT IT S AUTHORIZED LOCATION
LIMITED WARRANTY
I. CUSTOMER OBLIGATIONS
A. CUSTOMER assumes full responsibility that this Radio Shack computer hardware purchased (the " Equipment "), and any copies of Radio
Shack software included with the Equipment or licensed separately (the "So ftware ") meets the specifications, capacity , capabilities,
versatility, and other requirements of CUSTOMER .
B. CUSTOMER assumes full responsib1l1ty for the condition and effectiveness of the operating env ironm ent in which the Equipment and Software
are to function , and for its installation .
11. RADIO SHACK LIMITED WARRANTIES AND CONDITIONS OF SALE
A. For a per i od of ninety (90) calendar days from the date of the Radio Shack sales document received upon purchase of the Equ ip ment . RADIO
SHACK warrants to the original CUSTOMER that the Equ i pment and the medium upon which the Software is stored is free from manufacturing
defects . THIS WARRANTY IS ONLY APPLIC~BLE TO PURCHASES OF RADIO S HACK EQUIPMENT BY THE ORIGINAL CUSTOMER FROM
RADIO SHACK COMPANY-OWNED COMPUTER CENTERS, RETAIL STORES AND FROM RADIO SHACK FRANCHISEES AND DEALERS AT ITS
AUTHORIZED LOCATION . The warranty is void if the Equipment's case or cabinet has been opened. or if the Equipment or Softwa re has been
sub1ected to improper or abnormal use . If a manufacturing defect is discovered during the stated warranty period . the defective Equipmen t
must be returned to a Radio Shack Computer Center . a Radio Shack retail store. participating Radio Shack franchisee or Radio Shack dealer
for repair , along with a copy of the sales document or lease agreement. The original CUSTOMER 'S sole and exclusive remedy in the event of
a defect is limited to the correction of the defect by repair . rep la cement . or refund of the purchase price . at RADIO SHACK 'S election and sole
expense RADIO SHACK has no obligation to replace or repair expendable ite ms .
B. RADIO SHACK makes no warranty as to the des ign, capability , capacity , or suitability for use of the Software , except as provided in this
paragraph . Software is licensed on an " AS I S" basis , without warranty . The original CUSTOMER 'S exclusive remedy, in the event of a
Software manufacturing defect, is its repair or replacement within thirty (30) calendar days of the date of the Radio Shack sales document
received upon license of the Software. The defective Software shall be returned to a Radio Shack Computer Center , a Radio Shack re tail store.
participating Rad io Shack franchisee or Radio Shack dealer along with the sales document.
C Except as provided herein no employee , agent , franchisee . dealer or other person is authorized to g ive any warranties of any nature on behalf
of RADIO SHACK .
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Ill. LIMITATION OF LIABILITY
A. EXCEPT AS PROVIDED HEREIN , RADIO SHACK SHALL HAVE NO LIABILITY OR RESPONSIBILITY TO CUSTOMER OR ANY OTHER PERSON
OR ENTITY WITH RESPECT TO ANY LIABILITY , LOSS OR DAMAGE CAUSED OR ALLEGED TO BE CAUSED DIRECTLY OR INDIRECTLY BY
" EQUIPMENT" OR " SOFTWARE " SOLD , LEASED. LICENSED OR FURNISHED BY RADIO SHACK , INCLUDING , BUT NOT LIMITED TO , ANY
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NOTWITHSTANDING THE ABOVE LIMITATION S AND WARRANTIES . RADIO SHACK 'S LIABILITY HEREUNDER FOR DAMAGES INCURRED BY
CUSTOMER OR OTHERS SHALL NOT EXCEED THE AMOUNT PAID BY CUSTOMER FOR THE PARTICULAR "EQUIPMENT" OR " SOFTWARE "
INVOLVED.
B. RADIO SHACK shall not be liable for any damages caused by delay in delivering or furnishing Equipment and / or Software .
C. No action arising out of any claimed breach of this Warranty or transactions under this Warranty may be brought more than two ( 2) years
after the cause of action has accrued or more than four (4) years after the date of the Radio Shack sales document for the Equipment or
Software . whichever first occurs .
D. Some states do not allow the limitation or exc l us i on of incidental or consequential damages , so the above limitation(s) or exclusion(s) may
not apply to CUSTOMER .
IV. RADIO SHACK SOFTWARE LICENSE
RADIO SHACK grants to CUSTOMER a non-exclusive. paid-up license to use the RADIO SHACK Software on one computer . subject to the following
provisions :
A. Excep t as otherwise provided in th is Software License , applicable copyright laws shall apply to the Software .
B. T itle to the med ium on which the Software is recorded (cassette and / or diskette) or stored ( ROM) is transferred to CUSTOMER , but not tit le to
the Software .
C. CUSTOMER may use Software on one host computer and access that Software through one or more terminals if the Software permits this
function.
D. CUSTOMER shall not use , make , manufacture . or reproduce copies of Software except for use on one computer and as is specifically
provided in this Software License . Customer is expressly prohib ited from disassembling the Software .
E. CUSTOMER is permitted to make additional copies of the Software only for backup or archival purposes or if additional copies are required in
the operation of one computer with the Software . but only to the extent the Software allows a backup copy to be made . However . for
TRSDOS Software , CUSTOMER is permitted to make a limited number of additional copies for CUSTOMER 'S own use .
F. CUSTOMER may resell or distribute unmodif ied copies of the Software provided CUSTOMER ha s purchased one coµy of the Software for each
one sold or distributed . The provisions of th is Software License shall also be applicable to third parties receiving copies of the Software from
CUSTOMER.
G. All copyright notices shall be retained on all copies of the Software .
V. APPLICABILITY OF WARRANTY
A. The terms and conditions of this Warranty are applicable as between RADIO S HA CK and CUSTOMER to either a sale of the Equipment and / or
Software License to CUSTOMER or to a transact i on whereby RADIO SHACK sells or conveys such Equipment to a third party for lease to
CUSTOMER .
B. The li mitations of liability and Warranty provisions here in shall inure to the benef it of RADIO SHACK , the author , owner and / or licensor of the
Software and any manufacturer of the Equ ipment sold by RADIO SHACK .
VI. STATE LAW RIGHTS
The warranties granted herein give the original CUSTOMER s pecific legal rights . and the original CUSTOMER may have other rights which vary
from state to state.

The FCC Wants You to Know ...
This equipment generates and uses radio frequency energy. If not installed and used prop-
erly, that is , in strict accordance with the manufacturer's instructions, it may cause interfer-
ence to radio and television reception.
It has been type tested and found to comply with the limits for a Class B 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 in a residential instal-
lation. However, there is no guarantee -that interference will not occur in a particular
installation.
If this equipment does cause interference to radio or television reception, which can be
determined by turning the equipment off and on , the user is encouraged to try to correct the
interference by one or more of the following measures:
• Reorient the receiving antenna
• Relocate the computer with respect to the receiver
• Move the computer away from the receiver
• Plug the computer into a different outlet so that computer and receiver are on different
branch circuits.
If necessary, you should consult the dealer or an experienced radio/television technician for
additional suggestions. You may find the following booklet prepared by the Federal Com-
munications Commission helpful: How to Identify and Resolve Radio-TV Interference
Problems.
This booklet is available from the US Government Printing Office, Washington, DC
20402, Stock No. 004-000-00345-4.
Warning .
This equipment has been certified to comply with the limits for a Class B computing device,
pursuant to Subpart J of Part 15 of FCC Rules. Only peripherals (computer input/output
devices, terminals, printers, etc.) certified to comply with the Class B limits may be attached
to this computer. Operation with non-certified peripherals is likely to result in interference to
radio and TV reception.
In te lligent Mo dem DC-2212 Op eration Manual
©1984 Ta ndy Co rp oration
Fo rt Worth, Texas 76102 U.S.A.
A ll Rights Reser ve d.
Reproduction or use, without express written permission from Tandy Co rpora ti on, of any portion of
this manual is prohibit ed . While reasona bl e e ff orts ha ve been taken in the prepara ti on of this manual
to ass ur e its accuracy, Tandy Co rp ora ti on ass um es no li ability resulting from any errors or omissions
in th is manual, or from the use of the in fo rmation co ntained herein.
IO 9 8 7 6 5 4 3 2

Contents
Getting To Know Your Modem . . . . . . . . . . . . . . .. . . . . . . . . . .. . . . . . . . . . . . . . 3
Setting Up the DC-22I2 Modem ................................... 4
Setting Communications Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Sample Programming Sessions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Log On CompuServe ..................................... ·. 8
Answer or Originate A Call Automatically . . . . . . . . . . . . . . . . . . . . 9
Change Advanced Programming Options . . . . . . . . . . . . . . . . . . . . . 9
Manual Mode Operation ......................................... I0
TRS-XENIX Operation ........................................... II
Wake Up, DC-2212! ................................................... 13
Switching From High to Low Baud Operation ....................... 13
Entering Command Receptive State ................................ 14
Automatic Mode Operations ........................................... 15
Automatic Answer Mode ......................................... 15
Automatic Originate Mode ........................................ 16
Line Status Conditions ........................................... 17
Dial Sequence Emergency Shutdown Command ...................... 18
How To Abort An On-Line Status .................................. 19
Analog Self-Test Mode ........................................... 21
Programming Commands ............................................. 23
Connecting the Modem ............................................... 35
Connecting to the Telephone ...................................... 36
Connecting to a Power Source ..................................... 37
Connecting to Your Computer ..................................... 37

Optional Modem Configurations ....................................... 39
Multi-Line Phone Operation ...................................... 39
RS-232 Protocol Extension ........................................ 39
Synchronous Mode Operation ..................................... 39
'froubleshooting ......................................... , ....... 41
Specifications .............. ' .. ~ .................................. 43
Index ................................................................ 47
Figure 1.
Figure 2.
Figure 3.
Table 1.
Table 2.
Table 3.
Table 4.
Table 5.
List of Illustrations
Front Control Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Rear Panel Connections ................................. 35
Connecting the Modem ................................. 36
List of Tables
DC-2212 Programming Commands ........................ 14
Slow Dialing Speed Rate ................................. 26
Fast Dialing Speed Rate .................................. 26
Valid Dialer Digits and Codes ............................. 28
Modem-to-Computer Cables and Connection Points .......... 37
11

Getting to Know Your Modem
Tandy's DC-2212 high speed, intelligent modem has all the features needed to enhance
your data-communications applications -including a data output rate four times faster
than that of the standard "dumb" modem.
This direct-connect, 212-A type modem is not only designed with standard automatic
dial, answer, and disconnect features, but a wide range of system configuration
enhancements as well. After dialing is completed, the DC-2212 modem monitors the
call and reports its progress to your computer over the serial RS-232-C link. These
functions, which are roughly equivalent to the functions of an operator making a call,
include:
• Waiting while the phone rings until the dialed number answers
• Hanging up and redialing later if the number is busy, or if the call has not been
answered after a specified length of time
• Hanging up the handset at the end of a completed call
Each call-progress signal -ring-back, no tone, busy tone, or dial tone -that the
modem detects is printed out as a serial status message on your display. An auto-
disconnect feature permits the modem to disconnect if a carrier signal is not maintained
after a data call has been set up or upon command. This feature is useful in preventing
the tie-up of expensive computer facilities due to wrong-number calls, failure of the
distant party to disconnect from a time-sharing system, or line failures.
All functions of the DC-2212 modem are controlled by ASCII (American National
Standard Code for Information Interchange) encoded commands that you program from
your computer keyboard over the serial RS-232-C interface. For example, you can
control the selection of pulse- or tone-dialing through the dialer programming mode
command, or the number of times the phone is to ring before being answered by using
the advanced programming enable command.
3

One of its advanced features is the ability to determine your computer's communications
parameters -baud rate, data bits per word, parity, and stop bits per word -and
adjust its own operation to meet system requirements, using a simple command code
sequence.
Designed with a high degree of intelligence, the DC-2212 allows you to operate your
computer virtually unattended when linked to a telephone -making possible a wide
range of telecommunications applications. Used with the proper applications software
package, the modem is capable of performing operations such as electronic mail and
shopping, central-data-base access, home banking and remote-peripheral sharing.
This manual, in the sections following, will describe how you can use the DC-2212
modem to call (originate) a host computer or information service, or receive (answer) a
call from another computer, either manually or automatically. Additionally, you will
learn how using the modem 's advanced features can actually enhance your
communications applications.
Setting Up the DC-2212 Modem
When you have made the peripheral connections as outlined on page 35, Connecting
the Modem, you are ready to power-up and load your communications software.
When the power is freshly applied, several of the LED indicators on the modem's front
panel will illuminate -and remain lit, depending on the status of the computer's
protocol. These six indicators show the modem's internal and external operation status.
POWER SWITCH
Figure 1. Front Control Panel
4

CD High Speed. Lights when the modem is in high speed (1200 baud)
communications.
@ Off-Hook. Lights when your modem is on-line (connected to the phone lines).
@ Terminal Ready. Lights when the terminal is supplying DTR.
© Carrier Detect. Lights when the modem receives a carrier tone or generates a
false carrier.
® Transmit Data. Lights when the modem is transmitting data.
® Receive Data. Lights when the modem is receiving data.
Your DC-2212 modem permits a computer or terminal to communicate with a remote
computer by converting that computer's electrical signals into audio tones that can be
efficiently handled by the telephone system.
Likewise, the audio tones that the modem receives are converted back to electrical
signals that are understood by the computer.
Setting Communications Parameters
The DC-2212 modem provides data communications in full- or half-duplex mode at
either 0-300 bits-per-second (asynchronous) or 1200 bps (synchronous or
asynchronous). Transmission speed is always selected by the originating modem.
Automatic originate mode operation is a default (preset) condition upon first power-
up. When opened for programming with the auto-baud-rate-detect code (Wake Up,
DC-2212!), the modem automatically synchronizes the baud rate, word length, parity,
and stop-bit numbers of your computer system.
When programmed for automatic answer mode operation, the modem adapts the
communications protocol of the remote computer system upon receipt of a telephone-
line-ringing signal. This auto-answer feature makes it possible for data transmission to
occur between a remote terminal interfaced to a modem and your computer -without
intervention from the operator.
Refer to your computer owner's manual or applications software user's guide if you
require instructions on setting communications parameters.
5

Sample Programming Applications
A Videotex Plus communications package for TRS-80 Model II, 12, and 16
microcomputers is used in the sample programming sessions following. With this
package, you are able to communicate with a variety of information services and host
computer systems. The examples are designed to familiarize you with some of the
operations the modem is capable of performing.
A log-on session gets you started by showing how the modem is used to log on an
information service. The remaining sessio ns demonstrate how you can program the
modem to perform operations, such as dialing your ca ll s and answering the phone
automatically. Additionally, you will learn how the advanced programming options are
used to enhance automatic operations.
Programming the modem . ..
All modem functions are controlled by ASCII encoded commands that you send from
your computer keyboard. A two-key code sequence called the wake-up command is
used to open the modem for programming. (See Wake Up, DC-2212! for an
explanation of the importance of this command 's function, page 13.)
When this two-key code sequence is issued, the DC-2212 automatically adapts the
speed, word length, number bits, and parity of your computer. When answering calls,
the modem adapts to the speed, word length, number bits, and parity of the calling
modem.
l. Check again that all peripherals are correctly connected (C onnecting the Modem
page 35) and receiving power.
2. Flip the power switch on the modem 's front panel to the ON position. Carrier
Detect (CD) indicator lights.
3. Load and run the Videotex Plus communications program as described in your
user's guide.
4. At TR SD 0 S Re ad Y , type l.JI DT Ei< ( ENTER ). Terminal Ready (TR) indicator
lights. The screen show s:
t.!IDTD( 01,00.00
CoPYri9ht 1983 Tandy Corp,
Al 1Ri9hts Rese nied
6

5. Set the baud rate, word size, parity, and stop bits that you want to use.
6. Open the DC-2212 modem for programming by typing the wake-up command
sequence. Press 00.
7. When the * echoes on your computer screen, enter the command that tells the
modem to display or list its current parameters. Press CD to send the List
Command. These parameters appear on the screen as:
PHONE ND:
10 BITS/CHAR:Y
ABORT CHAR:1L!H
LOSS OF CARR:Y
SEND SPACE:N
RECE I t,JE SPACE: Y
ABORT ENABLE:Y
HIGH SPEED:Y
ANALOG LOOP:N
ORIG MODE:Y
MANUAL MODE:N
FORCE CARDET:Y
PULSE DIAL:Y
SLOW DIAL:Y
Since the modem is defaulted for automatic originate mode operation when cold-
started, the list should show:
DRIG:Y
MANUAL:N
where Y and N indicates a yes or no response to the prompt.
If you are set up for 1200 baud communications, the list will show
HI GH SPEED : Y. You can also see that the modem is currently programmed to
dial any phone number entered using pulse signaling (PULSE DI AL : Y) at a
slow dialing rate (SLOW DI AL: Y). (See page 23 for the List Command, under
Programming Commands, for a complete discussion of the modem's parameters
menu.
After the parameters are listed, the modem returns to the command receptive state
(off-line status) where it waits for further instructions.
7

... log on CompuServe Information Service
CompuServe Information Service is widely known for its numerous on-line services for
both business- and home-computer owners. Dedicated telephone numbers in major cities
provide you access to CompuServe. Use your information service user's guide to find
out how to contact and use the service.
Since the modem is already in the command receptive state -waiting for your
command -all you have to do to begin the log-on is prepare it to dial the information
service access number. For dialing instructions, refer to the D Command under
Programming Commands for the valid dialing codes, page 27.
I. Press ([) to place the modem in the dialer programming mode.
Example:
If you enter I( 111 )555-1234 as your local 12(7)(7) baud access number, the sequence
appears as:
01(111)555-1234
2. When the phone number is properly formatted, press 00 to force the modem to
seize the telephone lines and to begin dialing the number. O.ffHook (OH)
indicator lights.
The screen shows DI AL I NG • • , then the number string that was dialed.
3. When the ringing stops, the modem sends the message:
ON LINE ORIGINATE
Other line conditions (BUSY, DEAD LINE , NO TONE) that can be detected by
the modem are discussed in Automatic Mode Operations, page 17 .
4. Press (CTRLl© (break character C ··· appears) and type the User ID number that
you received with the software package when the screen prompts:
User ID:
5. Next, type the password that you received with the software package when the
prompt appears:
Your password is not printed on the screen to retain its secrecy.
8

At this point, your log on to CompuServe is complete and you may begin using the
service. To use other information services and host systems, simply substitute the
appropriate dialog as provided in the information service user's guide.
. . . answer or originate a call automatically
When communications is completed with the information service, the modem reverts
into the disconnect mode. To program the modem to resume monitoring the telephone
lines for incoming calls, enter:
Wake up.
Select answer mode.
Do it!!!
TR indicator lights. The modem prompts the screen by sending the message
AU T0 ANSWER, and waits for the telephone to ring.
Later that day, you may decide to use the service again. Assuming that no other call
has been made and the modem is still waiting for the phone to ring, you would program
the modem to dial (originate) the number by entering:
Wake up.
Select originate mode.
Do it!!!
OH Indicator lights. The modem seizes the phone lines and begins dialing the access
number that you used earlier. Remember, any number entered in dialer memory will
remain intact until a new number is entered or the modem is turned off. When the call
is completed, the modem goes back off-line and communications ends with the
DISCONNECT prompt.
Answering and originating calls automatically is discussed in more detail under
Automatic Mode Operations, page 15 .
. . . change advanced programming options
The DC-2212 modem is equipped to perform many operations that are equivalent to the
functions of an operator making a call.
When the modem detects a busy signal after dialing a number, the message BUSY is
printed on the screen. (DC-2212 enters the disconnect mode.) In a similar situation, a
telephone operator might say: "I'm sorry, that number is busy. Would you like to place
the call again later?" You would hang up the receiver, wait about 30 minutes, and try
to make the call again.
9

With the modem programmed to redial a number found busy, the second attempt is
made after a 6Cl-second delay. When a busy signal is received, the cycle -disconnect,
wait, redial , disconnect, wait, . . . - continues until the number of programmed
attempts is completed, or you abort the process with the * command.
To change the defaulted dial attempts setting or any of the advanced parameter settings,
follow these steps:
00
CD
Wake up.
Bring the advanced programming options to
the screen.
1. Press (ENTER ). The DIAL ATTEMPTS prompt appears on the screen.
DIAL ATTEMPTS:l?
2. Change the defaulted number to a value other than 1 by typing in that new
number. Press (ENTER) (five times) until you have exited the menu.
3. Press CID , enter the phone number to be dialed, and press 00 .
Other automatic operations that you can control through the advanced programming
command (I Command) are explained in Programming Commands, page 31.
Manual Mode Operation
When operating in manual mode, you control the system by manually dialing and
answering the telephone. Manual mode (answer or originate) is useful when you want to
talk by telephone to a friend on the other side of town, and later, exchange computer
data without redialing.
Example:
The phone rings and you answer by picking up the receiver. After talking awhile
to a friend, you decide to exchange information by computer (telecommunications)
-without breaking voice call.
1. Your friend selects to be the originate station, while you are the answer station.
Set up your modem by entering:
Wake up.
Select manual mode.
Select answer mode.
10

2. Give your friend time to set up the originate modem by entering ~000. You
may recall that automatic originate mode is a preset condition at initial power-up.
3. When you hear the originate modem 's carrier tone (a high-pitched sound), press
00. Your modem seizes the line and lets you know that communications can take
place by sending the message 0 N L I NE ANSWER.
4. The answer station always issues the X command first. After hearing the answer
modem's carrier tone, the originate station sends the X command to make the
connection and the screen prompts 0 N L I NE 0 RI GI NATE.
Be sure to keep quiet when the handset is off-hook -noise picked up could cause
errors in the data being passed by the modems.
After the data has been successfully transmitted, the modem sends the message
DI SC 0 NNECT. Be careful when you hang up the telephone since slamming or
dropping the phone back on the hook while the modems are 'controlling the lines could
disrupt carrier long enough to start a loss-of-carrier disconnect sequence.
To return to voice communications after transmitting data:
1. Carefully pick up the receiver (both modems).
2. Type at the keyboard that you will be aborting carrier. For example, you might
signal your friend by entering:
THAT'S ALL THERE IS FOR NOW.I AM ABORTING CARRIER,
3. After making sure your handset is off-hook, enter the abort character sequence
(see page 21, "Transmission of the Abort Character") to force the modem off
line. For Model II, 12, and 16 users, this sequence is CONTROL T. Press
(CONTROL) CTJ .
After 3 seconds of inactivity, your modem logs out with the disconnect prompt and
your friend 's modem (if automatic) shuts down, too.
TRS-XENIX Operation
Your DC-2212 modem is configured to operate with a TRS-XENlX Operating System
(Version 1.3.2. or later). This section will be helpful in explaining how using the
DC-2212 with TRS-XENlX differs from operations in other modes.
When you are ready to use the modem with TRS-XENIX, you should be familiar with
the following functions: enable logins, disable logins, and dial out.
11

To access TRS-XENlX , you must log in as the super-user -or "roo t" - and tell the
system which serial channel (A or B) you plan to use. For example, enable a channel
by typing:
e n ab 1 e t t Y 0 1 ( ENTER )
e n ab 1e t t }' 0 2 (ENTER)
or Enable Channel A
Enable Channel B
The serial channel that is used must be disabled before using the cu command for
making a call (originate mode) or "dia l out." To disable a channel (A or 8), type:
d i s ab 1e t t Y 0 1 ( ENTER ) or d i s ab 1e t t y 0 2 (ENTER)
To operate in automatic answer mode:
Set the AUTO-ANSWER switch, located on the modem's rear panel, to the position
nearest the DB-25 jack and power up the DC-2212. From a power-on condition, the
DC-2212 will power up into the call-waiting state and monitor the telephone line for an
incoming call. When DTR is asserted (this happens when logins are allowed using the
enable command), the modem will pick up the call and assume auto-answer, 10-bit
word, 1200 baud operation.
Note: This switch is only read (active) when power is freshly applied to a DC-2212
operating TRS-XENIX . Be sure you tum the modem's power OFF, then ON again,
whenever you change the position of the switch.
Dial Out
Set the AUTO-ANSWER switch on the modem 's rear panel to the position nearest the
DB-25 jack, and power up the DC-2212. Program the modem to automatically dial a
call by entering the cu command:
cu phone number -s 1200 ( ENTER )
where phone number is the number you want dialed and the -s value is the baud rate
selected. To dial the call out on Channel B, type:
cu phone number -s 1200 -a / dev /cua1 -I / dev /cul1 ( ENTER )
When the prompt connected appears, you can begin communications. See your
TRS-XENIX system's documentation for more information on using a modem with
TRS-XENIX .
Note: cu will assume tone dialing. If your phone system requires pulse (rotary) dialing,
insert " r" before entering the phone number.
12
....

Wake Up, DC-2212!
At the initial power-up -after breaking connection with the telephone lines -the
modem enters an off-line (or waiting) mode and remains in this mode until you tell
(command) it what to do next.
The wake-up command is the only command the DC-2212 modem responds to while
in the off-line mode (from power-up). It is the auto-baud-rate-detect code sequence
which forces the modem from the off-line status into the command receptive state.
To send this command from your computer or terminal keyboard, press 00 . The
screen echoes *.
You may have noticed that the * was not ec;hoed until you pressed CJ, the second key
in the auto-baud-rate-detect code sequence. That's because both keys are needed to
determine the baud rate, bit count, and parity (if any) you are using at your computer
or terminal. When the correct baud rate is detected, this character * (2A, in hex code)
is output.
Switching From High to Low Baud Operation
The DC-2212 modem automatically synchronizes with the standard 75, 110, 150, 300,
600, and 1200 baud rates.
Switching from a high speed (1200 baud) to a low speed (300 baud) operation occurs
when you wake up the modem. If the wake-up code sequence detects a 1200 baud rate,
the modem communicates in high speed. If it is awakened at 300 baud, low speed
operation is used.
What happens if you wake up the modem in low speed mode, but want to call a high
speed modem? If that modem has low-speed detection circuitry, it selects 300 baud
operation. If it cannot shift baud rates, the originating modem must change its
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operation. The originating station always determines the speed of operation when one
DC-2212 modem calls another DC-2212 modem.
Entering Command Receptive State (CRS)
The modem is now in the command receptive state and is waiting for you to begin
programming or setting the internal switches that tell it what operations are to be
performed.
The wake-up command opens the DC-2212 for programming and precedes any
command issued while the modem is in the command receptive state. The list of
commands that the modem expects to receive are briefly described in Table I. A
detailed description of each command's function is provided later in this manual in the
section Programming Commands.
Command
L, I
A, a
0,o
T, t
R, r
s, s
F, f
Q,q
D,d
@
M,m
G,g
E, e
I, i
c, c
x, x
DC-2212 Programming Commands
Function
List user options/switches
Answer mode operation
Originate mode operatipn (default)
Tone dialing global command
Rotary (pulse) dialing command (default)
Slow dialing speed (default)
Fast dialing speed
Flag for selt-test
Dialer programming mode enable
Refresh abort character
Manual/automatic toggle command (automatic default)
Forced carrier detect toggle (default)
Echo disable/enable command
Advanced programming feature enable
Clear out all user options
Exit command receptive state and execute current switches
Table 1. DC-2212 Programming Commands
These commands can be entered in upper- or lowercase characters. Seven-bit words and
even or odd parity are possible. If parity is set up on your computer terminal before you
send the wake-up command, the modem automatically corrects its parity parameters.
Seven-bit words with two-stop bits are also operable.
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Automatic Mode Operations
The DC-2212 modem can be programmed to make a call or answer your telephone
automatically. In the automatic mode operation, you can call an information service
without picking up the phone -just type in the phone number on your computer
keyboard. You can also tell the modem to answer your telephone. When the answer
command is received, an auto-answer feature enables the modem to enter the answer
mode automatically when the phone-line-ringing is detected.
Automatic Answer Mode
To program your DC-2212 modem to automatically answer incoming calls:
I. Press 00 to wake up the modem, then press 00 to send the answer
command. Remember, if this is a cold start-up, the modem will be defaulted to
the automatic originate mode and you will need to press 00 to select the answer
mode. (To check that all the parameters are set correctly, press OJ for the list
command and look for the DR I G MODE and MANUAL MODE parameters.) The
display shows:
Then, press 00 to force the modem to seize the phone lines.
2. The modem prompts AUTO ANSWER and waits for the telephone to ring.
3. When the phone rings, the modem begins counting the rings as you have
programmed (I command, page 31). When the modem answers the line, the
computer displays the message:
ON LINE ANSWER
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When carrier is asserted by your modem, the calling modem replies with its c::irrier.
The modems are now in an on-line status and telecommunications can begin.
If the modem does not receive a valid tone from the other modem within 13 seconds, it
aborts the call with the statement ND TONE (no carrier tone). The DC-2212 modem
then reverts back into the auto-answer mode and outputs AU T0 ANSWER to your
computer.
When either modem breaks connection after a successful data exchange, the DC-2212
alerts you by sending the message DI SC 0 NNEC T and returns to the auto-answer mode
and monitors the lines. As long as the modem is in the auto-answer mode, it will
continue to monitor the telephone lines for an incoming call.
Regardless of the number of calls received and the number of calls that transferred
computer data to your system, the DC-2212 modem always returns to the call-waiting
state. You can turn off this call-waiting mode by pressing 0 (CJ is not needed).
When the modem sees the * (* will not be echoed), it will return to the command
receptive state.
Note: The parameters are still not changed! If you want to return to the auto-answer
mode, send the X command . If you want to make an outside call, press CQJ (originate
mode) to take the modem out of the answer mode.
Automatic Originate Mode
When you want to call another modem, but do not want to dial it yourself, you can
program the modem to dial it in the auto-originate mode.
1. Press 00 to wake up the modem. When cold-started, the modem defaults to
automatic originate mode. Press OJ to check the modem's current parameters.
These commands echoe as:
If your listing does not show MANUAL MODE: N and DR I G MODE: Y, press
00 CQJ.
2. Use the D command to program the dialer memory, - that is, tell the modem
what number you want dialed. After typing in the phone number, press 00 to
force the modem out of the command receptive state and to begin dialing the
number. (See dialing instructions and codes under Programming Commands,
page 27.)
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