Installation and Operation Instructions Chapter 1 Dial-up Modem Introduction The DLM4100ET has been configured by the factory: Standard dialing commands are provided by the PC or PLC connected
to the DLM4100ET. The DLM4100ET Dial-Up Modem has been pre-configured at the factory
for typical PLC to PC use. It is intended for use as a remote/receiver
in industrial applications under temperature conditions that would
render a standard dial-up modem inoperative or unreliable. Since
it has been pre-configured, in most cases the only command strings
required are for dialing and hang-up. The command instructions
to be entered in either a PC program or a PLC configuration program
for dial-up operation are summarized in Appendix C. The DLM4100ET is available as an enclosure mounted unit. When powered up, a red Power LED will be lit. The amber Carrier LED will be on when carrier communication has been established between modems. In place of a standard speaker, a piezo-element transducer has been utilized to provide reliable audio output throughout the entire temperature range of the modem. The DLM4100ET has been specifically configured for industrial
data communication between a PLC and a PC. The active RS-232 DB-9
pin connections are as follows (with respect to the RS-232 port
on the modem):
RTS, CTS, DSR and DTR are not active or connected on the DLM4100ET. The DLM4100ET is not intended for the wide spectrum of applications usually associated with a full-featured dial-up/leased line modem. As a result, many options such as data compression, leased line operation, error correction, or external telephone jack are not available with the DLM4100ET. For a full-featured dial-up/leased line modem, consider a standard temperature range modem such as the Data-Linc DLM4000. DO NOT USE ANY CONVENTIONAL MODEM INITIALIZATION STRINGS WHEN
PREPARING THE DLM4100ET TO DIAL. ANY COMMANDS OTHER THAN THOSE
REFERRED TO IN THIS MANUAL CAN CHANGE THE PRECONFIGURATION OF
THE DLM4100ET AND MAKE IT INOPERATIVE FOR PLC COMMUNICATION. Unpacking the DLM4100ET Carefully inspect the package for shipping damage. If damage is
found, immediately repack the modem in the original packing material
and contact your dealer. The LED Indicators
Phone: (425)882-2206
FAX: (425)867-0865
Data-Linc Group
DLM4100ET Extended Temperature Dial-up Modem
The DLM4100ET is a dial-up modem designed and manufactured to
operate at the full industrial temperature range of -40C to +85C.
It is DC powered with an operating voltage range of +9VDC to +15VDC.
A 120VAC to +12VDC (unregulated) wall transformer type power supply
is provided with the modem.
10-bit word:
-8 data bits, 1 stop bit, 1 start bit, no parity
or
-7 data bits, 1 stop bit, 1 start bit, even/odd parity
or
-7 data bits, 2 stop bits, 1 start bit, no parity.
As factory configured, the DLM4100ET will auto-answer on the first
ring from any incoming call.
Pin
Function
1
Carrier Detect
2
Transmit Data (Data from the modem to the PLC or PC.)
3
Receive Data (Data into the modem from the PLC or PC.)
5
Signal Ground
The complete modem package includes:
The LED indicators on the front panel of modem display the current
modem operation and status as explained below:
O
Green
Send Data (TXD)
Flashes when the modem is sending data to the remote modem or
when receiving data from the local computer.
I
Yellow
Receive Data (RXD)
Flashes when the modem is receiving data from the remote modem
or when sending data to the local computer.
C
Amber
Carrier Detect (CD)
On when remote modem carrier is detected.
P
Red
Power
On when there is power to the modem.
The power connector is a barrel jack, which accepts the barrel
plug from the power adapter that comes with your modem.
Note: NEVER use an out-of-specification power adapter. It may
damage your modem.
There is no power switch on the modem. It is turned on by connecting
the barrel jack from the 120VAC-to-12VDC adapter to the power
receptacle on the end of the modem. Always turn your computer
on before turning on your modem, and turn your modem off before
turning off your computer.
The DB-9F (female) connector on the end of the modem is to accept the RS-232 cable which connects the your computer or PLC to the modem. It utilizes standard RS-232C pin assignments and electronic standards.
There is one modular RJ-11 jack on the end of the modem. This is for the connection to the dial-up phone line.
The Serial Port and the RS-232 Cable:
Your computer or PLC must have an industry standard RS-232 serial port in order to use the DLM4100ET in RS-232 mode. If you do not have one, consult your dealer to acquire an RS-232 interface card for your computer.
You also need a serial cable between your modem and your PLC or computer (serial port). The correct cable for your modem has the following characteristics:
- DB-9M (male) connector at one end to match the modem connector.
- A connector that fits your computer's serial port at the other end. For a PC user, the standard serial port card has a DB25M or DB9M connector so that your cable will have a DB25F or DB9F connector at the other end.
- The pin-to-pin connection of the cable will usually be "Straight Through." Since your modem complies with industry standards in pin assignment, most standard modem cables should fit. However, you may refer to the appendices in this manual to check the pin assignment of the DLM4100ETconnector.
The Telephone Line Test and the Phone Cable
The quality of the telephone line significantly affects the reliability
of data communications. Make sure that both the telephone system
and telephone lines are in good order before the modem is connected.
Before installing the modem, test the line condition by attaching
a telephone handset. You should hear a clear dial tone. Then try
placing a few calls. If the calls do not go through properly or
the sound quality is not loud and clear, you probably have a poor
quality telephone line. Contact your telephone service provider
to have the problem cleared. It is preferable to connect your
modem directly to an outside telephone line. If you connect to
a private branch exchange (PBX) telephone system you may have
to use a modified dial-out command string and to notify callers
that must use modified call-in procedures.
Any good, operational, standard 4 -wire phone cable can be used to connect the incoming telephone line to the modem.
The Installation of the DLM4100
Your modem is a compact design small enough to fit in a small
area, or can be mounted in any convenient location using the enclosure
mounting holes. The distance between the computer and modem is
determined by the length of the RS232C cable. However, an RS-232
cable should not be longer than 50ft, as signal distortion and
interference may occur. A suitable location to place your modem
shall be:
- Where you can easily reach a reliable AC power source, a wall outlet of good quality telephone line, and not too far from the computer.
- Where you can easily see the LED indicators, reach the power switch on the modem, and listen to the modem speaker.
Once you have chosen a proper location for your modem, follow the procedures below to connect the hardware:
- Make sure that both the modem and the computer are turned off.
- Connect the modem to the computer: Plug the DB-9M end of the RS-232
cable to the modem, and plug the other end of the cable to your
computer's serial port. Secure all of the screws on the connectors.
Note: Verify and write down to which serial port (COM1 to COM4) your modem is connected to the computer, as the port number is required for communications software installation. Refer to the manual of your serial interface card or your terminal to find out how the port is configured. - Connect the modem to the incoming telephone line: Use an appropriate cable to connect the incoming line to the RJ11 jack on the modem. Be sure that you have tested the line condition as described in the previous section.
- Supply power to the modem: Insert the cable-plug end of the power adapter into the power jack in the rear panel of the modem. Be sure to use only the adapter that comes with your modem.
The Communications Software
Since your modem follows the industrial standard in-modem command
set, most of the popular on-the-shelf communications software
packages will work with it.
Pay particular attention to the following parameter settings, as unsuccessful modem operation is often due to incorrect setting of:
- Serial port number - COM1 to COM4.
- Communications protocol - CCITT or Bell.
- Data format - number of data bits, parity and number of stop bits.
(The DLM4100ET operates using 10 bit words -------- )
In order to communicate successfully, the protocol and data format of the two modems on-line must be set to 10-bit word as described previously. Otherwise, the connection may not be established or the data received may be unreadable (garbled).
Dialing String Listed below are some examples which will illustrate the use of
dialing prefix strings. (For the meaning of each command refer
to the Command List in Appendix C).
Chapter 2 Modem Operation Factory Default Profile Modes of Operation Data Mode Command Mode Command Line Format The "AT" Prefix The Command Line A backspace can be used to edit the command string. Command strings
can only be edited before they are executed. (See "Re-Execute
Last Command, below).A backspace erases the previous character
in the command line. Register S5 allows the user to select a character
other than a backspace to edit the command string. Re-Execute Last Command Omitted Parameters The Escape Sequence Result Codes
Since the DLM4100ET comes from the factory pre-configured, an
Initialization String should not be used so that the DLM4100ET
pre-configuration is not changed. There are a limited number of
dialing string prefixes that can be used with the DLM4100ET. Some
of the primary Command Prefixes are:
Dial String
ATDT
Escape Sequence
+++
Hang Up
ATH0
ATS0=2
Instructs the modem to auto-answer an incoming call on the second
ring.
ATS6=10DP
Instructs the modem to wait for 10 seconds, then, use pulse dialing
method to dial.
ATM2L3DT
Turns on modem audio monitoring at all times with high volume.
ATB0DT
Use CCITT protocol to establish connection with the remote modem
and selects tone- dialing method.
AT&P1DP
Pulse dials with the make/break ratio of 33/67 (in most European
countries).
AT&P0DP
Pulse dials with make/break ratio of 39/61 (in USA).
This chapter describes selected important DLM4100ET functions. It is designed to help you understand the function of your modem and how to use it.
Your modem contains configuration profiles that are maintained
even after the modem is turned off. These are permanently fixed
at the factory.
The DLM4100ET has two operating modes; Data and Command. Modem
setup is performed in Command mode. Communications occurs in Data
mode.
The DLM4100ET enters Data mode after a link has been established
and the "CONNECT" result code has been issued. In this mode, all
signals are sent to the remote modem on the I pin (pin 2) of the
DB-9 connector. Demodulated signals from the remote modem are
received on the O pin (pin 3) of the DB-9 connector. The DLM4100ET
exits from Data mode any time carrier is dropped or the escape
sequence is received.
The DLM4100ET enters Command mode on power-up, reset, disconnect,
or receipt of the escape sequence. Commands are input to the modem
on I and result codes are issued on O. Data that is sent on the
I line which does not conform to the command format is ignored.
Modem commands must follow a specific format. Each command must
begin with the "AT" prefix. The modem stores command lines in
the command buffer. Command strings stored in the command buffer
are executed upon receipt of a Carriage Return. Command strings
can be edited while in the command buffer up until the command
is executed.
Each command must be preceded by the "AT" prefix. The "A" and
the "T" can both be upper or lower case, but not one upper and
the other lower case. The prefix identifies the speed and parity
of the host. The DLM4100ET measures the width of incoming bits
to calculate speed and compares parity bits of the two characters
("A" and "T") to determine parity.
A command line may include a string of commands. Commands are
executed in the order they appear in the command string. A Carriage
Return terminates the command string and triggers the DLM4100ET
to execute the commands. Register S3 allows the user to select
a character other than a Carriage Return to terminate the command
string and execute the command. The command buffer holds up to
40 characters including the "AT" prefix. Spaces may be added for
clarity to a command string without counting as characters. If
the command buffer overflows, the modem issues an "ERROR" result
code, and the commands are not executed.
The "A/" command causes the DLM4100ET to re-execute the command
stored in the command buffer. A command string remains in the
buffer until a new command is issued or power to the modem is
turned off.
Many commands require a parameter to specify the function, such
as L being Speaker volume. A number, "n", defines the operational
status of "L". For example, L3 would result in the speaker operating
at it's loudest setting. If no number is included in a command
string, for those items requiring a number, the default is "0".
The escape sequence switches the modem from Data mode to Command
mode while maintaining a communication link. The escape sequence
uses an escape character, set by register S2, entered three times
in succession. The default character is "+". A guard timer before
and after the sequence prevents normal data from triggering an
escape.
The DLM4100ET issues a result code after each action. Result codes
may be numeric codes, plain English statements, or disabled. Numeric
result codes end with a Carriage Return, statements start and
end with a Line Feed and a Carriage Return. Result codes are sent
at the speed determined by the "AT" prefix.
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