Campbell | DC112 | Operator`s manual | Campbell DC112 Operator`s manual

DC112 MODEM
OPERATOR’S MANUAL
REVISION: 12/91
COPYRIGHT  1987, 1989 CAMPBELL SCIENTIFIC, INC.
WARRANTY AND ASSISTANCE
The DC112 MODEM is warranted by CAMPBELL SCIENTIFIC, INC. to be free from defects in materials
and workmanship under normal use and service for twelve (12) months from date of shipment unless
specified otherwise. Batteries have no warranty. CAMPBELL SCIENTIFIC, INC.'s obligation under this
warranty is limited to repairing or replacing (at CAMPBELL SCIENTIFIC, INC.'s option) defective products.
The customer shall assume all costs of removing, reinstalling, and shipping defective products to
CAMPBELL SCIENTIFIC, INC. CAMPBELL SCIENTIFIC, INC. will return such products by surface
carrier prepaid. This warranty shall not apply to any CAMPBELL SCIENTIFIC, INC. products which have
been subjected to modification, misuse, neglect, accidents of nature, or shipping damage. This warranty
is in lieu of all other warranties, expressed or implied, including warranties of merchantability or fitness for
a particular purpose. CAMPBELL SCIENTIFIC, INC. is not liable for special, indirect, incidental, or
consequential damages.
Products may not be returned without prior authorization. To obtain a Returned Materials Authorization
(RMA), contact CAMPBELL SCIENTIFIC, INC., phone (435) 753-2342. After an applications engineer
determines the nature of the problem, an RMA number will be issued. Please write this number clearly on
the outside of the shipping container. CAMPBELL SCIENTIFIC's shipping address is:
CAMPBELL SCIENTIFIC, INC.
RMA#_____
815 West 1800 North
Logan, Utah 84321-1784
CAMPBELL SCIENTIFIC, INC. does not accept collect calls.
Non-warranty products returned for repair should be accompanied by a purchase order to cover the repair.
815 W. 1800 N.
Logan, UT 84321-1784
USA
Phone (435) 753-2342
FAX (435) 750-9540
www.campbellsci.com
Campbell Scientific Canada Corp.
11564 -149th Street
Edmonton, Alberta T5M 1W7
CANADA
Phone (403) 454-2505
FAX (403) 454-2655
Campbell Scientific Ltd.
Campbell Park
80 Hathern Road
Shepshed, Leics. LE12 9RP
ENGLAND
Phone (44)-50960-1141
FAX (44)-50960-1091
DC112 MODEM
1. FEATURES
•
Bell 212A and CCITT V.22 Compatible
•
Full Duplex at 300 and 1200 Baud
•
"AT" Command Set
•
RJ-11C Telephone Jack
•
Pulse or Tone Dialing
•
Direct Connection to and powered by:
- CSI dataloggers
- CSI PC201 Card in IBM PC Compatible
- Computer
- CSI PC203 Power-up Control Box
- CSI SC532 RS232 Interface
•
Signal Level Connects/Disconnects 5Vdc
External Power minimizing current drain
2. DESCRIPTION
The DC112 Modem is a 300/1200 baud modem
employing the popular "AT" command set. Its
primary use is as a remote site modem
connected to a CSI datalogger. The modem is
powered and enabled by the battery-powered
datalogger. When disabled, the DC112 draws
less than 2 uA from the datalogger 5 Vdc
output.
FIGURE 1. Connector Pinout
4.
(output) Rx Data- serial data from modem.
5. (input) Modem Enable- a logic high turns
on 5V power to the modem. A logic low
shuts off 5V power to the modem.
6. (input) Serial Device Enable - a logic high
disables communication with the modem
without removing power or changing the
modem's mode. This input can be negated
with an internal jumper.
7. No Connection
8. No Connection
A Hayes or Hayes compatible modem is used at
the computer site.
The DC112 can be used as an originate modem
at the datalogger site. To originate a call to the
computer, the datalogger is programmed using
Instruction 97. For more information refer to the
datalogger manual, Instruction 97.
The DC112 is connected to a CSI datalogger by
using a 9-pin subminiature D connector cable.
The pinout of the connector is shown in Figure
1. The pins used by the modem are (all levels
are OV for logic low, 5V for logic high):
1. (input) +5 V regulated supply
2. (input) Ground
3. (output) Ring- a logic high signifies a ring
signal has been detected.
9. (input) Tx Data- serial data to the modem.
3. SPECIFICATIONS
Current Drain: Approximately 2 uA when
modem enable is low; 35 mA when modem
enable is high but phone is on-hook; 48 mA
when off-hook.
Supply Requirements: A single 5 V regulated
power supply.
Logic Levels: Below 1.5 V inputs a low state
and above 3.5 V inputs a high state. A low
voltage level on the Tx data input (pin 9) and Rx
data output (pin 4) represents a mark.
Operational from -25oC to +50oC
Size: 4 3/8" x 3" x 1"
Weight: 12 oz.
1
DC112 MODEM
4. INSTALLATION
Your DC112 is designed to be used on standard
device telephone lines. The DC112 connects to
the telephone line by means of a USOC RJ11C
jack. Connection to telephone companyprovided coin service (central office
implemented systems) is prohibited.
Connection to party lines service is subject to
State tariffs.
Connect the cable from the telephone jack to
the modem Figure 2. Connection to the
datalogger is done with a Campbell Scientific
SC12 Cable. Connect the 14 awg grounding
wire (provided with the DC112) to the grounding
terminal (GND) on the DC112 and to the
datalogger ground. If the enclosure has a
grounded bus bar, then connect the ground wire
to the bus bar instead of the datalogger ground.
The datalogger ground should be tied to earth
ground. See the grounding section of the
datalogger manual.
The goal of the telephone company is to provide
you with the best service it can. In order to do
this, it may occasionally be necessary for them
to make changes in their equipment,
operations, or procedures. If these changes
might affect your service or the operation of
your equipment, the telephone company will
give you notice, in writing, to allow you to make
any changes necessary to maintain
uninterrupted service.
If you have any questions about your telephone
line, such as how many pieces of equipment
you can connect to it, the telephone company
will provide this information upon request.
In certain circumstances, it may be necessary
for the telephone company to request
information from you concerning the equipment
which you have connected to your telephone
line. Upon request of the telephone company,
provide the FCC registration number and the
ringer equivalence number (REN) of the
equipment which is connected to your line; both
of these items are listed on the equipment label.
The sum of all of the REN's on your telephone
lines should be less than five in order to assure
proper service from the telephone company. In
some cases, a sum of five may not be usable
on a given line.
FIGURE 2. RJ11C Phone Modem Connections
2
DC112 MODEM
Remote datalogger installations require a
telephone surge protector (Model 2372-01)
unless the telephone company confirms a surge
protector has already been installed at the
remote site (Figure 3). Connect the 14 awg
grounding wire (provided with the DC112) to the
grounding terminal (GND) on the DC112 and to
the datalogger ground. If the enclosure has a
grounded bus bar, then connect the ground wire
to the bus bar instead of the datalogger ground.
The datalogger ground should be tied to earth
ground. See the grounding section of the
datalogger manual.
FIGURE 3. Burial Phone Line to Remote Telephone Modem
3
DC112 MODEM
5. IF PROBLEMS ARISE
If any of your telephone equipment is not
operating properly, you should immediately
remove it from your telephone line, as it may
cause harm to the telephone network. If the
telephone company notes a problem, they may
temporarily discontinue service. When
practical, they will notify you in advance of this
disconnection. If advance notice is not feasible,
you will be notified as soon as possible. When
you are notified, you will be given the
opportunity to correct the problem and informed
of your right to file a complaint with the FCC.
For assistance in installation or for repair,
telephone (801) 753-2342 or write to Campbell
Scientific, Inc., P.O. Box 551, Logan, Utah
84321. To comply with FCC Rules and
Regulations, all repairs on the DC112 Modem
will be performed by Campbell Scientific, Inc. or
an authorized agent of Campbell Scientific, Inc.
6. THEORY OF OPERATION
The DC112 modem is used to transmit data over
bandwidth-limited channels such as telephone
lines by modulating audio tones, using Frequency
Shift Keying (FSK) at 300 baud, or Phase Shift
Keying (PSK) at 1200 baud.
The telephone company gives a 40 to 150
VRMS, 20 Hz signal on the phone lines to
signify a ring, which is typically on for 2 seconds
and off for 4 seconds. The ring detection
circuitry is continuously powered but draws less
than 2 uA. The ring signal is passed on to the
datalogger through an opto-coupler. The
datalogger responds by raising the Modem
Enable line which enables the 5Vdc power to
the modem. The modem then answers and
remains off-hook until it loses the carrier or the
datalogger lowers the Modem Enable line. The
datalogger lowers the Modem Enable line by
remote command or after 40 seconds in the
absence of a command. When the Modem
Enable line goes low, the 5Vdc power is
removed from the modem circuitry, dropping
power to the off-hook relay and thus placing the
phone line on-hook.
To reject noise common to both phone lines
and to satisfy registration requirements, the
modem circuitry is electrically isolated from the
phone lines by using an opto-isolator and
coupling transformer.
6.1 JUMPER CONFIGURATION
The DC112 has 5 user-changeable jumpers;
one at location C8 and four at location H15 as
shown in Figure 4. As shipped, only one jumper
is in place, H15 1 to 8. The following table lists
the jumper meanings. After removing a jumper,
store it on a single pin of the terminal.
FIGURE 4. Jumper Locations
4
DC112 MODEM
TABLE 1. Jumper Settings
JUMPER
PINS
MEANING
FACTORY SETTING
1. H15
2. H15
3. H15
4. H15
5. C8
1 to 8
2 to 7
3 to 6
4 to 5
1 to 2
Result Codes Enabled
Auto-Answer Disabled
Enable CCITT V.22
Do not use
Non-datalogger Site
Jumper in Place
Jumper not in Place
Jumper not in Place
Jumper not in Place
Jumper not in Place
JUMPER 1 - Result codes (Appendix A) are
sent to your terminal screen.
JUMPER 2 - Auto answer is disabled by putting
the jumper in place. This option is used only
when the modem is not to answer a call. For
example: The DC112 is connected to a phone
line which is to be used part time for voice
communication. In this situation it is best to
have the datalogger call the computer.
JUMPER 3 - Selects Bell 212A (U.S. and
Canada) or CCITT V.22 (Foreign). This does
not mean that the DC112 is tested and
approved for all foreign countries.
CCITT is an international consultative
committee that sets international
communications usage standards. V.22 is a
standard that the DC112 meets for
communicating at 1200 baud.
JUMPER 5 - Non datalogger site. This option
when enabled keeps the printer enable line from
disabling the transmit data line. This option is
provided because of the CR10 datalogger's
ability to synchronously address peripherals
connected to the 9 pin port (CR10 Manual,
Section 6.2). This Jumper is only used when
the DC112 is used as originate modem at the
computer.
Jumpers 1, 2, and 3 determine the state of the
modem when power is switched on by Modem
Enable or the ATZ command is executed.
Other functions which are fixed by hardware
are:
Numeric Result Codes
Full Duplex
Command Characters Echoed
Both the jumper selectable and fixed functions
can be changed by appropriate "AT" commands
(see Appendix A).
5
APPENDIX A. "AT" COMMAND SUMMARY
This manual does not attempt to be a primer on
the "AT" command set. The commands are
therefore only summarized below. For most
applications, the modem commands are issued
automatically by the PC208 software. The
commands apply only when the modem is used
as an originate modem, which is not the primary
use of this modem. Except as noted, all
commands begin with "AT" and end with
carriage return. As an example, the command
ATDT5551212 followed by carriage return will
tone dial the number that follows the ATDT,
then go on-line and wait up to 30 seconds for
the remote modem carrier. If the carrier is
detected, the result code 1 will be returned,
otherwise the result code 3 will be returned, and
the modem will return to the command mode.
COMMANDS:
COMMANDS TO CHANGE DEFAULT MODES:
R
Call an originate modem
B
CCITT mode
B1
BELL 212A mode
C
Carrier off
C1
Carrier on
E
Commands not echoed
E1
Commands echoed
F
Half duplex
F1
Full duplex
Q
Return result codes
Q1
Disable result codes
Sr?
What is the value in register r
AT
Prefix to all commands (except /A)
Sr=n Set register r to value n
A/
Repeat last command (not followed by
carriage return)
V
Digit result codes
D
Dial
V1
Word result codes
P
Pulse
T
Tone
0..9
Telephone number digits
W
Wait for another dial tone
;
Return to command state after dialing
,
Pause
Z
Reset to default settings
A
Answer without ring
H
Hang up
O
Go to on-line state
RESULT CODES:
0
OK
1
Connect
2
Ring
3
No Carrier
4
Error
REGISTERS:
S0
Rings before auto-answer (0..255)
S6
Wait for dial tone (2..255 seconds)
S7
Wait for remote carrier (1..255 seconds)
S8
Comma pause time (0..255 seconds)
S10 Delay time between loss of carrier and
hang up (1..255 in 10th of seconds)
A-1
APPENDIX B. FCC WARNING TO USERS OF
CLASS A COMPUTING DEVICES
WARNING: This equipment generates, uses,
and can radiate radio frequency energy, and if
not installed and used in accordance with the
instruction manual, may cause interference to
radio communications. It has been tested and
found to comply with the limits for a Class A
computing device pursuant to Subpart J of Part
15 of FCC Rules, which are designed to provide
reasonable protection against such interference
when operated in a COMMERCIAL
ENVIRONMENT. Operation of this equipment
in a residential area may cause interference to
radio and television reception. The operator
must take whatever measures are necessary to
correct the interference.
B-1
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