Cermetek DataSheet for product XE2486AD

Preliminary

XE2486AD

October 2007

New Generation of XE2486 Modems

Description

Features

The XE2486AD is the third generation XE2486 modem

Small Size: 1.2 inches by 0.955 inches by 0.39 inches

from Xecom. It provides a complete, 2400 bps global

thick.

modem for the ‘86 footprint. The XE2486AD uses the

Data transfer at rates from 300 bps to 2400 bps

new Xecom XE2400G modem to continue Xecom’s

support of loyal customers who designed the XE2486

Modem Control and Configuration via industry

standard AT Commands.

into their systems since 1996.

Supports V.42 and MNP error correction

The XE2486AD provides traditional Xecom features

such as the transferable FCC Part 68 Registration and

Shared Line Features prevent modem operation from

interfering with voice communications.

non volatile configuration storage, but also supports

new features such as error correction and global

Nonvolatile memory stores modem configuration.

compliance. Existing XE2486 users can choose to use

Complete integrated DAA.

the newer and less expensive model just as they have

User Transferrable FCC Part 68 Registration

always used the XE2486 or use the change as an

opportunity to enhance their product line.

UL60950compliant

Models

Complies with telephone networks around the world.

XE2486AD -V.22bis, DIP package

5 Volt Power operation;

XE2486AD BLOCK DIAGRAM

XECOM

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XE2486AD

XE2486AD Mechanical Specifications

Pin dimensions 0.010 inches by 0.020 inches

Inches

Dim.

Description

Min

Typ

Max

Min

Typ

Max

Module Height

0.380

0.390

0.400

9.67

9.91

10.16

Module Length

1.190

1.200

1.210

30.23

30.48

30.73

Module Width

0.950

0.955

0.960

24.13

24.26

24.38

Pin-to-Pin Spacing

0.090

0.100

0.110

2.29

2.54

2.79

Pin-to-Edge

0.040

0.050

0.060

1.02

1.27

1.52

Pin Row Length

1.090

1.100

1.110

27.69

27.94

28.19

Pin Row to Pin Row

0.790

0.800

0.810

20.07

20.32

20.57

Edge to Pin Row

0.070

0.080

0.090

1.78

2.03

2.29

Pin Length

0.120

0.130

0.140

3.05

3.30

3.56

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XE2486AD

XE2486AD Pin Configuration

XE2486AD (TopView)

Ring • 1

/RTS

Tip

RESET

GND

N/C

VCC

N/C

SPKR

/DCD

N/C

/CTS

N/C

/RI

N/C

/DSR

N/C

/DTR

TXD

/N/C

RXD

Pin Descriptions

PIN NAME

DESCRIPTION

Ring

The Ring and Tip signals provide modem the connection to the telephone line. FCC

Part 68 Rules require a 1500 volt isolation barrier between the telephone line and all

other circuits. This isolation must be preserved throughout the system.

The telephone company places a DC “Battery” voltage across Tip and Ring on public

switched telephone lines. The XE2486AD will operate regardless of the polarity of this

“Battery” voltage. The “Battery” voltage drives up to 100 milliamps of DC loop current.

UL60950 requires minimum creepage and clearances distances to be maintained between

Tip and Ring and all other circuits. Clearance is the shortest distance between conductive

circuits; creepage is the distance between conductive surfaces along the surface

Tip

The Ring and Tip signals provide modem the connection to the telephone line. FCC

Part 68 Rules require a 1500 volt isolation barrier between the telephone line and all

other circuits. This isolation must be preserved throughout the system.

UL60950 requires minimum creepage and clearances distances to be maintained between

Tip and Ring and all other circuits. Clearance is the shortest distance between conductive

circuits; creepage is the distance between conductive surfaces along the surface

3,4

N/C

No Connection

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XE2486AD

XE2486AD Pin Descriptions (continued)

NAME

DESCRIPTION

SPKR

SPKR provides a Pulse Width Modulated version of the signal on Tip and Ring allow.

The signal on SPKR is controlled by the ATL and ATM commands.

6-9

N/C

No Connection

TXD

TXD provides the path for transmitted data and modem commands to be passed from

the host terminal equipment to the modem.

RXD

RXD provides the path for received data and modem responses to be sent from the

modem to the host terminal equipment.

N/C

No Connection

/DTR

/DTR is an active low input to the modem.An active /DTR signal traditionally indicates

that the terminal is available for communications. The operation of /DTR is controlled

by the AT&D command.

/DSR

/DSR is active low output from the modem. The /DSR signal typically indicates that the

modem has established a communications link. The AT&S command determines the

operation of the /DSR signal.

/RI

The /RI signal reports on the presence of an incoming ring signal. When a ring occurs

across Tip and Ring, the /RI output goes low and toggles with the cadence of the ring

signal.

/CTS

/CTS is an active low output from the modem. When hardware flow control is active,

the modem asserts /CTS to indicate that it can accept data from the terminal equipment

on TXD.

/DCD

/DCD is an active low output from the modem. /DCD normally indicates the presence

of a valid carrier signal. TheAT&C command determines when the XE2486AD asserts

the /DCD signal.

N/C

No Connect

VCC

+5 Volt power for the modem

Ground

Ground provides the reference voltage for all host interface signals.

RESET

RESET is an active high input which initiates a modem hardware reset. RESET must

be active for a minimum of 100 milliseconds for a proper modem reset sequence. No

external reset is required; if none is used the RESET signal should be left open.

/RTS

/RTS is an active low input to the modem. When hardware flow control is active, /RTS

indicates to the modem that the host has data to send.

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XE2486AD

XE2486AD Electrical Specifications

Parameter

Min

Typ

Max

Units

Comments

VCC

4.75

5.0

5.25

Volts

ICC

100

On Line

Ring Voltage Detected

150

VRMS

Type B Ringer

Ring Frequency Detected

Type B Ringer

Telephone Loop Current

120

Line Impedance

600

Ohms

Data Transmit level

-12.0

-9.0

dBm

DTMF Transmit Level

-2.5

dBm

Avg over 3 second interval

Voh

2.4

5.0

Volts

Vol

0.4

Volts

Vih

2.0

5.0

Volts

Vil

-0.3

0.8

Volts

XE2486ADABSOLUTE MAXIMUM RATINGS

VCC

6.0Volts

Storage Temperature

-25 O C to +85 O C

1 Maximum OperatingTemperature Range

0 O C to +70 O C

MaximumTimeAbove Eutectic (183 O C)

90 seconds

Preheat Dwell Time

120 to 180 seconds

1 The XE2486AD can be ordered with an Operating Temperature of -40 O C to +85 O C at extra cost. Order

XE2486AD-ITR or to specify Industrial Temperature Range (ITR).

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XE2486AD

XE2486AD Typical Connection Diagram

Parts List for XE2486ADTypical Connection Diagram

Reference

Designation

Qty

Description

C1,C2

Cap.680pfd,Y2

PTC,TRF600-150

Notes:

Capacitors, C1 and C2, may be required for EMI filtering in your system. Without these components you may

experience unintended radiation when the telephone cable is attached. C1 and C2 are high-voltage capacitors.

We recommend the Novocap ES2211N681K502NSTM. This 680 pfd, 5000 volt capacitor will direct the high

frequency harmonics to the system ground.

3. F1 is a positive thermal coefficient (PTC) device which protects the modem from excessive current flow. These

devices are required for your system to pass UL60950. Fuses may be used in place of the PTC’s

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XE2486AD

XE2486AD Connection Data

The XE2486AD reports data on the current connection in response to the ATI11 command. Because

many of the reported parameters require an active connection, this command is best utilized from the on-

line command mode accessed with the escape sequence. The items shown in italics are only valid during

an active call.

The Connection Report is presented in two pages. The first page will be displayed on receipt of the ATI11

command. To move to the second page of the report hit any key. The table below describes the

information provided in the Connection Report.

REPORTED ITEM

DESCRIPTION

1 Last Connection

Not Used

2 Initial Transmit Carrier Rate

Upstream data rate first negotiated on last connection

3 Initial Receive Carrier Rate

Downstream data rate first negotiated on last connection

4 Final Transmit Carrier Rate

Upstream data rate at the end of the last connection

5 Final Receive Carrier Rate

Downstream data rate at the end of the last connection

6 Protocol Negotiation Result

Reports the error correction protocol negotiated on last connection; values

include LAPM/SREC, LAPM, MNP, and none.

7 Data Compression Result

Reports Link data compression protocol negotiated on last connection; values

include LAPM, MNP, V.42bis, V.44 and none.

8 Noise Level

Reports the estimated noise level in the modem signal.

9 Receive Signal Power Level

Reports the approximate level of the incoming modem signal.

10 Transmit Signal Power Level Reports the level of the outgoing modem signal.

11 Round Trip Delay

Reports how many milliseconds for the signal to be transmitted and returned.

12 Near Echo level

Not Used

13 Far Echo Level

Not Used

14 Transmit Frame Count

Reports the total number of LAPM frames transmitted thus far during the call.

15 Transmit Frame Error Count Reports the number of transmitted frames rejected during the current call.

16 Receive Frame Count

Reports the total number of LAPM frames received thus far during the call.

17 Transmit Frame Error Count Reports the number of received frames rejected during the current call.

18 Retrain by Local Modem

Reports the number of retrain and rate renegotiations requested by the local modem.

19 Retrain by Remote Modem

Reports the number of retrain and rate renegotiations requested by the remote modem.

20 Local Rate Renegotiation

Reports the number of rate renegotiations requested by the local modem.

21 Remote Rate Renegotiation

Reports the number of rate renegotiations requested by the remote modem.

22 Call Termination Cause

Reports the reason for termination of the last call; 0 indicates disconnect by local

modem command, 1 indicates loss of received modem carrier, 2 indicates a failed

call attempt, and 4 indicates a protocol failure.

23 Not Used

24 Not Used

25 Not Used

26 Not Used

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XE2486AD

XE2486AD AT Commands

The XE2486AD uses "AT" commands for

If the command buffer overflows, the modem

configuration and control. This section describes the

issues an "ERROR" result code, and the

AT command format and lists the commands,

command line is not executed. Register S3 allows

registers and result codes.

the user to select a character other than a carriage

return to terminate the command line.

Command Mode: The

XE2486AD

enters

command mode on power-up, reset, a lost

Re-Execute

Last

Command

The

connection, or receipt of the escape code. In

command causes the modem to re-execute the

command mode the modem accepts commands

last command line. This is the only command

from the host on transmit data. Appropriate result

which does not require the "AT" prefix.

codes are returned on received data.

Note: For backward compatibility some functions

Omitted Parameters - Most commands include

are controlled by more than one command. In these

a parameter which determines how the functions

instances the last command issued determines the

will be set. When the command parameter is

function setting.

omitted from the command string, it is assumed to

be a 0.

Command Line Format

AT commands follow a strict format.

Each

Escape Characters - A 3 character escape

command line, except A/, begins with the prefix

sequence may be entered to switch the modem

AT. The "A" and "T" may be both upper case or

into command mode while on line. The escape

both lower case but cannot be of different cases.

character, set by Register S2, must be entered 3

The modem determines data rate of the host

times in succession to execute the escape. An AT

equipment by measuring the width of the incoming

command must then be entered within the period

bits of the “A” and “T.”

defined by S12 to enter command mode. The

default escape sequence is "+++."

Multiple commands may be combined into a single

command line of up to 40 characters. Commands

Result Codes - The modem issues a result code

are executed in the sequence they appear upon

after each action. Result codes may be sent as

receipt of a carriage return. Spaces inserted into the

full words, one or two digit numeric codes, or may

command line are not placed in the buffer.

be disabled all together. Each result code ends

with a carriage return when numeric result codes

The command line can be edited with a backspace

are chosen. When full word result codes are

before it is executed. The backspace erases the

chosen, a Line Feed and Carriage Return precede

previous character in the command line. Register S5

and follow each result code.

allows the user to select a character other than

backspace to edit the command line.

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XE2486AD

CONVERTING FROM THE XE2486 TO THE XE2486AD

Xecom has been building the XE2486 Modem Module since 1996. While we would like to continue to

offer this modem without modification, the modem chip used to create the XE2486 has been discontinued

by our supplier. We have identified a suitable replacement for that discontinued chip but with new features

created over the last decade, we are concerned about compatibility with the old modem. To achieve

compatibility Xecom has loaded a modified modem configuration into the XE2486AD’s nonvolatile

memory. These changes will be active on power-up and maintained after a hard or soft reset. Below is a

list of the command changes.

Command

Factory Default

Xecom Nonvolatile Setting

ATB

B1; Select Bell 212A mode at 1200 bps

ATW

W0: Do not report protocol type

AT&C

&C1

&C0: /DCD active with no modem carrier detected

AT&D

&D2

&D0: Modem ignores status of /DTR

AT&K

&K3

&K0: Disable flow control

AT\N1

\N3

\N1: Error correction disabled;

AT\Q

\Q3

\Q0: Disable local flow control

AT%C

%C1

%C0: Disable data compression

AT+IFC

+IFC=2,2

+IFC=0,0: Disabled flow control in both directions

ATS6

S6=3

S6=2; Wait 2 seconds for dial tone

ATS7

S7=30

S7=30; Wait 30 seconds for carrier to be detected

ATS10

S10=20

S10=14; Disconnect after losing carrier for 1.4 seconds

ATS37

S37=0

S37=6; Default connect speed 2400 bps

Notes:

1) Using the AT&F command to return to factory defaults will cancel the configuration changes Xecom

loaded into nonvolatile memory and bring up the default settings supplied by the chip manufacturer. This

could prevent the modem from working in your application.

2) Any of these commands can be changed as required to meet system requirements. The changes only

attempt to duplicate the configuration of the XE2486AD in its default state.

3) The configuration required for your system can be loaded into the XE2486AD’s nonvolatile memory

using the AT&W command. The AT&W command stores the current configuration into nonvolatile

memory.

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XE2486AD

SWITCHING FROM THE XE2486 TO THE XE2486AD

Even with the default settings on the XE2486AD changed to match the XE2486. the /DCD and /DSR

signals operate differently than they did on the XE2486. The differences in operation are illustrated below.

/DCD Operation

The XE2486AD with the AT&C0 command setting offers fewer transitions on the /DCD line than does

the old XE2486. You need to be aware of these differences if you use these transitions to trigger action in

your code. The XE2486 returns the /DCD to the inactive state after 5 seconds when the modem drops

the line. The XE2486AD only goes inactive only during the power-on or reset sequences. The illustration

below shows the operation of DCD on the two modems

/DCDOperationwithAT&C0

/DSR Operation

As with the/DCD line the operation of the /DCD line differs between the XE2486AD and XE2486. AS

with the /DCD output the /DSR output on the XE2486 shows transitions each time the line is dropped. The

XE2486AD deactivates /DCD only on power cycling or reset.

/DSR Operation withAT&S0

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XE2486AD

XE2486AD AT Commands

An asterisk indicates the factory default

Ln - Speaker Volume - Selects level of speaker output.

n=0,1 LowVolume

A - Answer Command - Causes the modem to

n=2 Moderate Volume *

immediately go off-hook and attempt to a connection

n=3 HighVolume

Bn - Bell or CCITT default - Determines if the modem

Mn - Speaker Activity - Determines when the speaker

will prefer CCITT or Bell212A modulation at 1200 bps.

will be active.

n=0 Use CCITT V.22 at 1200 bps

n=0 Speaker off

n=1 Use Bell 212A at 1200 bps *

n=1 Speaker on until carrier received *

n=2 Speaker remains on

D - Dial Command - Causes the modem to go off-hook

n=3 Speaker on until DCD active

and dial. Below are the characters accepted in the

dialing string.

0-9,A-D, #, * = Dialing Digits

Nn - Link Negotiations - Selects how Register S37 will

be used to set the link negotiations

L = Redial Last Number Dialed

n=0

Connect only at the speed selected by S37

P = Pulse dial

n=1 Begin negotiations at the selected speed

S=n = Dial number stored in location n

but allow fallback *

T = Tone dial

W = Wait for dial tone

On - On Line - Puts the modem back into data mode

, = Pause for the duration of S8

from the on-line command mode.

! = Switch hook flash

n=0 Return On Line with no retrain *

; = Return to the command state

n=1 Initiate retrain while returning On line.

En-CommandEcho - Determines it the modem returns

Qn - Responses - Determines if the modem w