Cermetek Imodem series User manual

HIGH SPEED INTERNET MODEM FAMILY

microelectronics

Cermetek CH2156

CH2157

CH2158

CH2159

CH2160

3 I/O Ports Send Email Only.

2 I/O Ports & Temp Sense. Send Email Only.

Send Serial Data to/from Internal RAM. Send Email Only.

Send/Receive Data Internal Cache 4MEG RAM memory

Send/Receive Data. Streaming Data Format

TECHNICAL AND OPERATIONAL OVERVIEW

The iModem® Family of products are pin for pin compatible with the

CH179X and CH2056 modem products. Referring to Figure 1, the

CH21XXiModem®Familyconsistsofanindustrialgradehighspeed

modem module and a mP controller with associated internal logic.

The mP controller and the logic provide all the functions required for

internet communication via standard PSTN telephone lines. The

iModem® utilizes TCP, IP, PPP, PAP, SMTP and POP3 internet

protocols.

The iModem® requires an external RJ11C jack for the PSTN line

connection. An optional CCITT V.24 serial interface is required

when host processor control of the iModem® is either required or

desired in the specific application.

The iModem® receives iNet AT® commands from the host

processor or receives an event status flag on the Send Email

Control Pin (Pin #6) and proceeds to dial up the local ISP, log on

to the Internet and authenticate and verify user ID and password,

and either send or receive email depending on the command/

status flag received. All received emails are presented on the

RS232 interface for possible further host processing and reten-

tion.

The send and receive email function may be aborted at any time

during the email activity by activating the Send Email Control Pin

(Pin #6). This will cause the iModem® to terminate the email

activity and revert to the idle state.

The CH2158/9 and CH2160 iModem® products contain 32K of

extended memory and, therefore, can store limited emails for

later re-transmission. However, to fully utilize the receive email

capability, the RS232 interface should be operational.

FEATURES

• Uses Point-to-Point Protocol (PPP) with Password

Authentication Protocol (PAP) to connect to the Internet.

• Uses TCP/IP and Simple Mail Transfer Protocol (SMTP) to

send emails.

• On Demand and event driven email transmission and

reception.

• Programmable using serial interface or using PSTN.

• Remote programming using PSTN.

• Supports V.90, V.34bis, V.34, V.32, V.22bis, V.22A/B,

V.23, V.21, Bell 212A and 103.

• Supports V.80 Synchronous operation.

• Error correcting: V.42 LAMP, MNP 2-4 and MNP10.

• Data Compression: V.42bis and MNP5.

• MNP10 Data throughout enhancement for cellular

operation.

• DTE serial interface with speeds up to 230.4kbps.

• Automative baud rate adaptability utilizing speed

sensing, flow control and data buffers.

• Send & Receive FAX Class 1, Group 3 supported.

• Serial V.24, 5 volt interface.

• NVRAM directory and stored profiles.

• Standard AT Command structure with extensions.

• Cermetek iNet AT® Command extensions.

• Built-in DAA with 1500 VAC RMS isolation 2122V peak

surge protection.

• UL 1950 and CSA C22.2 950 (Third Edition) Listed,

Reference UL File E104957.

• FCC Part 68 Approved/DOT CSA CS-03 Part I

Approvable.

• Pin for Pin compatible with CH179X and HS Family of

modems.

• +5 Volt operation with zero power option.

• Small size: 1.35” x 1.97” x 0.61” (nominal).

TheiModem®s full range of capabilitiesandfeaturesallows forthree

methods of internet control as briefly described below.

Fully Autonomous On Demand and Event Driven Control.

This is the simplest method of operational control. Application of a

10ms TTL low going pulse (i.e., V<0.6) to the Send Email Control Pin

Each iModem®contains a fully functional 56kbps modem along

with the hardware and software needed to provide the internet

capability.

Because of this architecture, the iModem®has the unique ability to

operate as either an internet email transceiver or as simply a high

speed modem.

Additionally, the presence of the modem function allows for remote

access to reprogram or reconfigure the iModem® should the need

arise.

A validISPaccountIDandpasswordarerequiredtouse the internet

features. As a convenience to our customers, and to facilitate

operational use of the iModem®, Cermetek provides on an interim

basis a pre-programmed ISP account and password with each

iModem®delivered.

The iModem® Family is pin compatible with Cermetek’s HS Modem

familyand is FCCPart68approved and CanadianDOTapproveable.

The modules are designed for PCB throughhole mounting and are

1.35” x 1.97” x 0.61” in size.

INTRODUCTION

Cermetek’s iModem®Family of Internet products are the industries

first self contained modules providing a complete PSTN internet

communication solution. Further, the iModem® can operate

autonomously without the need for host processor intervention.

The iModem®Family offers a variety of internet communication

features ranging from simple on demand or event triggered email

transmission(CH2156)to full send and receive unlimited lengthemail

(CH2160). Internetcommunicationcontrolofthe iModem® exercised

by using one of the following basic control methods:

1. Fully Autonomous or event driven control requiring

no host processor intervention.

2. Semiautonomous control, requiring one command to be

issued from the host processor.

3. Complete host intervention and supervision.

Whenchoosingan implementation scheme utilizing a host processor,

the host controls the iModem® by issuing Cermetek iNet AT®

CommandswhichareextensionsofthestandardHayesAT command

set.

Serial Host Interface Buffer.

The iModem® utilizes a serial V.24 EIA 232-E 5V interface to

control the modem and communicate with the mP.

Figure 1. Functional Block Diagram of iModem®

The internal modem can be controlled with industry standard AT

commands and is compatible with available industry communica-

tion software.

Modem Control.

DESCRIPTION OF FUNCTIONAL BLOCKS AND DISCUS-

SION OF BASIC OPERATIONS

Figure 1 contains a functional block drawing of the iModem®.

Host Supervised Control.

This method is the most flexible, but requires the issuance of each

of the necessary iNet® AT Commands in the required order from

the host processor.

Although the RS232 DTE serial interface is required to be opera-

tional for this method of control, an additional feature of this

method is the ability of the host to override the pre-programmed

ISP and/or email address by simply including the applicable

information on the same line of code as the iNet AT® Command.

Host supervised control is recommended for debug activities.

Regardless of the method of iModem® control employed, the

iModem® will abort all email related activities if a low going TTL

pulse is presented to the Send Email Control Pin (PIN #6) at any

time during or after initiation of email send (@TD command) or

email Receive (@TG Command).

mP Controller.

The mP controller is a Motorola GP32 type controller with resident

internet protocol software and flash ROM. This controller

interprets the iNet AT® commands issued by the external host

processor or executes internal iNet AT® Command strings

depending on the iModem® control method employed by the

user.

Extended RAM.

Additional RAM is used as cache memory for the purpose of

email flow control and to facilitate transmission and reception of

large email files.

Control of the internet capabilities of the iModem® can be either

event driven, semiautonomous, or initiated and controlled by a

system level host processor.

Further, the iModem® can function as a 56K V.90 modem when

not connected to the internet.

Semiautonomous control is a special case of full Host Supervised

Control and relies on the pre-programmed default internet configu-

ration profile contained within the iModem®. Initiation of the email

activity occurs with the issuance of either the @TD iNet AT®

Command (to Deliver email) or the @TG command (to receive

email) by the host processor to the iModem®. PSTN dial-up, logon

& authentication and email transmission are performed automati-

cally by the iModem® in the same fashion as the on Demand

control method described above.

Semi-Autonomous Control.

This method requires a minimal amount of host processor

intervention and by necessity requires that the RS232 DTE serial

interface be operational.

The iModem® performs the following functions automatically:

1. Connects to ISP.

2. Authenticates user ID and logs onto internet.

3. Sends (or Receives) email to address specified using ISPs

SMTP or POP3 Mail Server.

4. Terminates ISP session after all data is sent (or received).

5. Sends message accepted Pulse to Pin 4 after all the ISP Mail

Server accepts the email.

Each iModem® product consists of a mP controller with Network

Protocols and Flash ROM, Extended RAM (CH2158/9 or CH2160

only), serial interface buffer, modulator/demodulator, modem

controller with error correction and data compression, nonvolatile

RAM and DAA.

(Pin #6) will cause the iModem® to send an email using its internal

default internet configuration profile. This profile is pre-programmed

at the factory and can be modified by the user. No host processor

intervention is required. The RS232 DTE serial interface is not

required for fully autonomous on demand and event driven control.

Typically this is accomplished by submitting the final end product

to an independent test house or consultant for evaluation. The

test/consultant then forwards the test results and applicable

documents to the regulatory agency. Contact Cermetek for a list

of suggested consultants.

Modulation/Demodulation/Error Correcting and Data

Compression

These functions are provided by an industry standard modem

ship set which has been adapted for use with the iModem®

Family.

Non-Volatile RAM (NVRAM).

NVRAM can store two user-customized configurations. The

AT&Wn command will store the active modem configuration in

one of two NVRAM locations as selected by an n of 0 or 1.

The modem communicates over the serial interface with the host

processor (referred to as a DTE or Data Terminal Equipment) at a

fixed speed regardless of the carrier line modulation speed (DCE)

of the PSTN modem connection. This eliminates the need to

have the DTE step up or step down in speed based on the

incoming or outgoing PSTN communication data rate.

Telephone Line Interface or DAA.

High performance modems are extremely sensitive to DAA (Data

Access Arrangement) performance. The difference between a

good modem and a fair one is in the DAA performance. The

iModem® family includes a unique low distortion DAA designed

for optimal performance over all PSTN line conditions thereby

achieving the most reliable and best performance PSTN connec-

tions.

The iModem® family is designed to meet North American

telephone standards as set by FCC Part 68 (USA) and CSA CS-

03 Part I (Canada). The PSTN line interface is UL1950 and CSA

C22-2 950 Listed (Third Edition) and is designed to meet 1500

VAC RMS isolation and provide 2122V peak surge protection.

Consequently, the iModem® family of products satisfies U.S. and

Canadian requirements, and will meet other international ap-

proval agency requirements that specify these levels of isolation.

Pins 1 and 2 function as both input and output connections to the

PSTN. To maximize field reliability in hostile environments, for

Canadian approval, for UL compliance, and also optionally for

FCC Part 15 compliance, these two pins must be routed through

an external network such as that described in Figure 6A and in

Cermetek Application Note #126.

Each iModem® product comes with FCC Part 68 approval and is

shipped from the factory with an FCC label indicating registration

number and ringer equivalent. This label should be prominently

displayed on the end product. With the exception of the U.S.,

most countries (including Canada) require submission of the final

product or system containing the iModem® to the appropriate

governing regulatory agency for approval.

The iModem® supports V.42 LAMP, MNP 2-4, MNP 10 error

correcting protocols and uses V.42bis data compression, allowing

data transmission rates of up to a maximum of 230.4kbps. These

high DTE data rates are supported by the iModem® serial inter-

face via its auto baud capability. Note that the maximum speed

attained is limited by the maximum speed available from the DTE

and not by the iModem®.

When the iModem® is operating in the internet state, all iNet AT®

Command communication between the iModem® and the host

processor (DTE) is conducted over the RS232 serial interface at

57.6kbps. When the iModem® is operating in the modem state,

communication with the DTE can be at any speed up to, and

including, 230.4kbps.

The resident Modulator/Demodulator supports line equalization and

forward error correction.

CONNECTING TO THE HOST UART

Since a modem communicates data serially and most host products

handle data in a parallel format, a UART is needed to make parallel-

to-serial and serial-to-parallel translations.

SUPPORTED FEATURES

Standard AT Command Set.

The iModem® supports the standard Hayes AT Command set with

extensions and can operate with industry standard communication

software. The AT commands are compatible with TR302.2/88-

08006. Refer to Table 6A & 6B for the command set description.

iNet AT® Command Set.

Cermetek has created a set of iNet AT® command extensions for

control of the internet communication function. These commands

operate in the same fashion as the standard AT commands. Refer

to Table 6C for the iNet AT® command extension set.

Serial Host Interface.

The iModem® operates in asynchronous mode and supports both

the full RS-232C/V.24 serial interface and a 5V, RS232-like interface

called V.24 (EIA-232-E). Signal levels are TTL rather than RS-232V

level compatible, which allows direct connection of the iModem® to

the host’s UART without level translating circuitry. See Table 3 for a

complete set of pin descriptions.

The iModem® is controlled by sending serial commands over TXD

and by monitoring serial status messages returned on RXD. All

other serial interface lines may be utilized for the convenience of a

particular application but are not required by the iModem®. Unused

outputs from the iModem® should be left unconnected. Unused

inputs should be tied to the proper logic level. See Table 3.

When using the iModem® exclusively in an event driven application,

the serial interface is not required.

Speaker Interface.

The SPK output reflects the receiver analog input and provides a

signal test that can be used to monitor call progress. The SPK

signal can drive a 300 ohm load directly. Typically, the SPK signal is

input into an audio power amplifier and the amplifier, in turn, drives

the speaker coil. The speaker is activated with the ATLn command,

where n is 0, 1, 2, or 3.

Increasing numbers correspond to higher volume. Figure 3 indi-

cates one method of driving an external 8 ohm speaker.

The AT&Yn command selects one of the stored modem configu-

rations to be automatically recalled and made active upon reset

or power up. The ATZn command immediately recalls and

activates a stored configuration. See Tables 7A and 7B for

storable S-Registers and Commands. The NVRAM can save up

to four telephone numbers, with up to 36 digits or modifiers in

each telephone number. The AT&Zn=s command will store s, the

telephone number dial string. The ATDS=n command will cause

the modem to dial one of the four stored telephone numbers. The

NVRAM storage location for the four telephone numbers is

selected by an n of 0, 1, 2, or 3

Bell 103 CCITT V.22

Bell 212A CCITT V.22bis

CCITT V.32

CCITT V.32bis

CCITT V.34

CCITT V.34bis

CCITT V.90

The Modulation/Demodulation scheme supports the industry

modem standards listed below.

Table 1. Data Formats Recognized by iModem® Family.

Table 2. iModem® Auto Configuration Based on DTE

Configuration.

Data Length No. of Character Length

Parity (No. of Bits) Stop Bits (No. of Bits)

None 7 2 10

Odd 7 1 10

Even 7 1 10

None 8 1 10

Odd 8 1 11*

Even 8 1 11*

*11 bit characters are sensed, but the parity bits are stripped off dur-

ing data transmission in Normal and Error Correction modes.

DTE Configuration iModem® Configuration

7 mark 7 none

7 space 8 none

8 mark 8 none

8 space 8 even.

Figure 4. Speaker Control Circuit.

Referring to Figure 5, use the variable resistor (POT) to set required

speaker volume.

To maintain FCC compliance, frequencies transmitted while in

voice mode should be between 300Hz and 3000Hz.

When voice and data are both being used, and the RXA and TXA

pins are active, it is typical for voice communication to precede data

communication. In this case, the following commands should be

used to configure the iModem® to allow for full utilization of the

Voice/Tone injection feature.

Voice/Tone Injection Port.

The iModem® Family provides pin T1 to allow the user to share the

PSTN line interface associated with the iModem® for voice and

DTMF applications. Figure 5 contains a schematic indicating one

possible configuration for voice/tone utilization.

All iModem® products are designed with pin T1 coupled directly to

the internal DAA. When using the iModem® in data mode, T1

should float and be disconnected from any potential signal because

any signal on T1 during data operation will affect the iModem®

output. If T1 is being asserted from another application, use a relay

or zero impedance switch to disconnect T1 when in data mode.

Automatic Speed/Format Sensing.

The iModem® supports both Command and Data modes of opera-

tion.

The iModem® can automatically determine the speed and format of

the data sent from the DTE over the serial interface; and can sense

the following broad range of speeds:

Figure 3. Zero Power Operation

The iModem® Family requires a single +5V +5% supply. It is

recommended that bypass capacitors be placed on the power

supply as close to the iModem® supply input pins as practical. It is

recommended that a 10 mF or greater tantalum capacitor in parallel

with a 0.1mF ceramic capacitor be used. The user must also

provide shielding from nearby sources of EMI, such as relays,

motors and other power supplies.

The iModem® is trained to a selected speed with an AT [CR] training

sequence. Thus, the DTE to modem serial interface speed can be

set independent of the DCE or line carrier connecting speed (with

minor restrictions, see the AT + MS command). This allows greater

flexibility when selecting DCE line carrier modulation speed thereby

affording the user with optimum data throughput performance. To

maximize effective modem data throughput speed, the DTE to mo-

dem serial interface speed should be set to the highest speed avail-

able without invoking the use of the iModem® built-in flow control.

Although flow control facilitates communication with higher speed

modes by the DTE, use of flow control causes an overall throughput

data rate penalty.

Power Supply.

The iModem® module is a complex set of sensitive sub-

systems. During the course of normal operation, the iModem®

decodes analog signals from the telephone line that are in

millivolt range. Steps must be taken by the user to guarantees

that power supply noise on all supply lines, including ground,

does not exceed 25 mV peak to peak. If necessary, use

dedicated power and ground planes. Failure to provide such

operating conditions could cause the iModem® to malfunction

or to function erratically.

The data formats in Table 1 are recognized by the iModem® family

of products.

The iModem® can sense data with mark or space parity and config-

ures itself as described in Table 2.

Referring to Figure 2, the controller activates the relay switch,

supplying power (+5V) to the iModem®. In this configuration, the

ring signal is used to “wake up” the iModem® when the iModem® is

in the power down state.

The pins of the iModem® will be in an undefined state when power

is switched off. This must be taken into consideration to assure that

no unwanted signals are presented to the iModem® during power

down.

Zero Power Mode.

If an application calls for zero power during standby periods, the

power may be switched off using external circuitry and then

reapplied when the iModem®’s RI pin becomes active. The

iModem® can thus be powered down to zero.

300, 600, 1200, 2400, 4800, 7200, 9600, 12000, 14400, 16800,

19200, 21600, 24000, 26400, 28800, 38400, 57600, 115200 and

230400bps.

Figure 5. iModem® Family Application Diagram

The iModem® will stay off-hook with its carrier on after the escape

sequence is received and it returns an OK status message when it is

ready to accept commands. The HS Modem can be put into data

mode by issuing the command ATO [CR].

THE COMMAND FORMAT

Typical commands consist of three elements:

1. The attention sequence,

2. The commands themselves and

3. A terminating carriage return.

WARNING: the iModem® family of products has been FCC Part

68 approved as data/FAX modems. Utilization of the Voice/Tone

Port requires further registration. The FCC requires that the

entire system, including the HS Modem and the handset or DTMF

transceiver, adhere to Part 68 rules.

AT [commands] [CR].

Where: [AT] represents attention sequence.

[commands] represents command strings.

[CR] represents carriage return (ASCII 13 or HEX 0D).

When entering commands to the modem, the backspace charac-

ter-control-H (ASCII 8 or HEX 08) can be used to edit mistakes.

“AT” and “A/” may not be edited however. Multiple commands may

be placed in the command line. A command line may be as long

as 40 characters, excluding the letters AT.

These commands disable auto-answer and eliminate hang-up due

to lack of carrier signal.

1. Enter: ATS0=0 [CR]

2. Enter: ATS7=255 [CR]

3. Enter: ATS10=255 [CR]

2. To switch to data mode, switch local voice source from

RXA and TXA:

(a) At the Originate Modem, enter: ATX1 [CR]

(b) At the Answer modem, enter: ATA [CR]

3. To disconnect (hang-up) a voice call or data call:

(a) Return to control mode by Entering: +++

(b) Enter: ATH [CR]

4. To place a voice call using the HS Modem DTMF facili

ties:

(a) Enter: ATDT(Tele)#;[CR]

(b) Then switch to local voice source

iModem® STATES

The iModem can be in either the Internet State or the Modem

State. Because the iModem® has the unique ability to

operate as either a high speed V.90 Modem or as an internet

email transceiver, the commands sent on TXD (or the status of

the Send Email Control Pin) determine operation.

iModem® Internet State.

The iModem® can be controlled by providing status flags on the

Send Email Control Pin (pin #6) or by sending ASCII commands via

the serial interface. Use of Pin #6 forces Internet email transmis-

sion operation. Upon successful transmission of an EMAIL, the

iModem® sends a momentary 100ms Low going TTL output pulse

on the Email Accepted Pin (Pin #8) indicating the email has been

received by the ISP Mail Server. If desired, a simple latch circuit

(see example in Figure 8) can be used to illuminate an LED to indi-

cate Email Accepted.

Thefollowingcommand sequences illustrate implementation of com-

mon voice/tone port applications.

1. To answer a voice call:

(a) Enter: ATH1 [CR]

(b) Switch local voice source into RXA and TXA

characters are sent to the modem), followed by 3 escape charac-

ters, followed by another guard time. At power-up, the guard time is

set to 1 second minimum, and the escape character is set as “+”.

These two parameters can be modified via registers S2 and S12,

respectively.

iModem® Modem State.

When in the Modem State, the iModem® can be in either command

mode or data mode. When the modem is idle, it is in command

mode by default and will recognize commands. When data trans-

mission is in progress, the iModem® is in the data mode state and

will not recognize commands. To force the iModem® to recognize

commands, the host must send an “escape sequence” to the

iModem® forcing it out of data mode and into command mode.

This message indicates command completion status. Refer to

Tables 5A, 5B and 5C for a complete list of status messages.

iModem® Training Command Sequence.

The iModem® is trained by sending it the following sequence:

Enter: AT[CR]

Where: A and T may be either upper or lower case but

must be the same case.

[CR] represents carriage return.

iModem® will respond with one of the following status messages,

depending on whether it is optioned for abbreviated or English

status messages.

Result: 0[CR] (Abbreviated form)

Result: [CR][LF][OK][CR][LF] (English form)

Where: [CR] represents carriage return (ASCII 13 or

HEX 0D)

[LF] represents line feed (ASCII 10 or HEX 0A)

The iModem® is now in idle, the DTE speed is set to a default

speed of 57.6kbs mode and the iModem® is ready to accept

commands.

As an alternate attention sequence “A/” may be sent which

behaves much like the AT sequence except that it causes the

previously entered command specified with an AT prefix to be

executed. When given, it must be in the upper case ASCII. No

carriage return is needed.

Extensions to the basic result code set can be specified by Register

S95, which allows for the use of result codes 40 - 64, 165 - 194.

Note: To obtain a detailed status report for a given modem commu-

nication configuration, use the AT/V1 command. Executing this

command at setup will cause the iModem® to connect and return a

message on line consisting of <DTE speed> <modulation> <error

protocol> <line speed of connection>.

AT COMMAND APPLICATIONS WHEN OPERATING THE

iModem® IN THE INTERNET STATE

Each iModem® is delivered with a pre-programmed ISP account ID

and password, local Sunnyvale, CA, dial-up ISP access phone

number and a default pre-programmed email subject title for use

on an interim basis.

Sending Emails.

If an email is to be sent utilizing the Cermetek pre-programmed

internet configuration profile (i.e., the pre-programmed ISP account

ID and password, and the pre-programmed destination email

address), issuing the @TD command is all that is needed to send

an email.

Example: Initiate dial-up and complete email

transmission using the pre-programmed

internet configuration profile.

Enter: @TD

The user may suppress certain subsets of the non-extended

result codes. This is accomplished by selecting subsets of the

result code set using the ATXn command, where n=0, 1, 2, 3.

Optionally, the user may specify an extended set of result codes

(codes above 35) by setting Register S95. See the detailed

description of result codes in Table 5A, Table 5B and Table 5C.

All AT commands, other than dialing commands, will be re-

sponded to with either an OK (short form result code 0) if the

command is valid or accepted, or with an ERROR (result code 4)

if the command is not recognized. The detail contained in the

error result code signaled to the DTE depends on the level of

message suppression employed by the user. As can be seen

from Tables 5A, 5B and 5C, specifying X4 allows the iModem® to

utilize the entire range of non-extended messages, whereas X0

suppresses all but the very basic result codes. Most of the result

codes allowed under X1, X2 and X3 are considered call progress

status codes and, in practice, are suppressed except for the case

of debugging activities. It is recommended that the non-extended

result codes be used in all cases.

It should be noted that the default connect result codes 9-20

indicate DTE connection speed, not Carrier Line DCE speed.

Hence, the iModem® will connect at a maximum speed of

57.6kbps (result code 18) unless the DTE is forced to a higher

speed by selection of data compression. In this case, the

maximum DTE to iModem® speed is 230.4kbps (result code 20).

All result codes have either a terse, short form version (which is

identified by a number followed by a [CR]) or a verbose long form

English-like message version (which is preceded and terminated

with a [CR] and line feed).

INITIALIZING THE iModem®

Before commands may be sent to the iModem®, the iModem®

must be initialized. This consists of two events:

1. Modem Reset. This is accomplished by applying a hardware

reset pulse to pin RST or by switching the power off and then

back on.

2. Initial Modem Training. The modem must be trained to the

host DTE speed and parity (odd, even, mark, space or none).

These activities are briefly described below.

Reset.

Upon applying power to the iModem®, the iModem® automati-

cally generates an internal reset pulse. The user can also reset

the modem externally by applying a high-going reset pulse to the

RST pin for at least 10ms after the +5V power supply has been

stabilized. Delay sending commands to iModem® for 900ms after

reset has been initiated to allow the iModem® time to properly

reconfigure.

On power up, or when reset is initiated either by command ATZ or

by the RST pin, the iModem® will reconfigure to it’s default state

with the line carrier modulation DCE speed set to 56 kbps.

If desired, any speed, error correction, or data compression

method available on the iModem® can be locked in, using the

AT\Nn and/or AT+MS commands.

Training the iModem®.

The iModem® must be trained to match the host DTE speed and

parity so that it is able to recognize serial asynchronous com-

mands sent to it by the DTE.

The DTE must retrain the iModem® each time a reset pulse is

applied on RST or after a RESET serial command has been

issued.

By way of example, the command below instructs the iModem® to

configure itself to not echo characters when in command mode

(E0) and then put itself in answer mode (A).

Enter: ATE0A[CR]

Standard AT Command Set.

The Hayes AT command set is divided into four types of com-

mands: dial modifiers, basic commands, ampersand and percent

commands. Refer to the complete list in Tables 6A and 6B.

STATUS MESSAGES AND RESULT CODES

A result code is issued by the iModem® to the DTE for all

commands executed by the iModem®, except dialing and internet

commands. Further, various activities on the PSTN are also

signaled to the DTE by the iModem®.

AT COMMAND APPLICATIONS WHEN OPERATING THE

iModem® IN THE MODEM STATE.

In the last example, the entire pre-programmed internet configu-

ration profile is over ridden.

Dialing A Phone Number.

The Dial command takes the form Dn, where n is a string of

characters. In the simplest form, n will be only the digits of the

phone number to be dialed.

Example: Dial Number.

Enter: AT D1234567

In response to this command, the iModem® dials the telephone

number “123-4567” and then waits for a carrier from the distant

modem. If no carrier is detected within a given time (the default

time is 30 seconds), the iModem® automatically releases the line

and sends a NO CARRIER result code.

The default email subject title is:

Cermetek Microelectronics iModem Email

Further, Input #1 and Input #2 status will also be transmitted. For

CH2156, CH2158/9 and CH2160, the default send email will be of

the form:

Remote Product Message

Input 1 High (or low)

Input 2 High (or low)

For CH2157, which contains an onboard temperature sensor, the

default send email is of the form:

Remote Product Message

Temperature xx (Reported in Fahrenheit)

Input High (or low)

To change the default internet configuration profile, refer to the

PROGRAMMING THE iMODEM® section of this data sheet.

Fully Autonomous Control.

If email is to be sent by activating the SEND EMAIL CONTROL

PIN (PIN#6), the iModem® will utilize the pre-programmed internet

configuration profile.

The iModem® is designed to allow the user to personalize the

default internet configuration profile by either using the PSTN to

dial up the iModem® or by using the RS232 host serial interface.

Once reconfigured, simply activating the SEND EMAIL CONTROL

PIN will automatically cause an email to be transmitted.

In a typical fully autonomous application, the user installs “as

received” the iModem® in the desired remote environment and

connects only the incoming PSTN to the systems jack.

Once the PSTN is connected, the user accesses the iModem®

and then re-configures the iModem® in situ. Upon completion of

the re-configuration activity, the iModem® can now be directed to

send emails from the remote environment by activating the SEND

EMAIL CONTROL pin.

Semi-Autonomous and Complete Host Intervention Control.

This method of control requires all commands to be issued in

serial fashion. The first example assumes that the pre-pro-

grammed ISP and email address is to be used.

A common host control application involves using the iModem®

pre-programmed internet configuration profile except for the local

access ISP phone number.

Example: Initiate dialup using a local ISP access

phone number different from the pre-

programmed number. Then complete

email transmission using the pre-

programmed ISP account, ID password

and email destination address.

Enter: @TN1234567 New Phone Number

Enter: @TD Initiate dialup and send email

In a slightly more complex example, the host controller over rides

both the ISP access phone number and the destination email

address. The email is then sent using the @TD command.

Example: Send email Overriding the pre-

programmed ISP local access phone

number and default pre-programmed

destination email address. For all other

parameters, use pre-programmed

information internet configuration

profile.

Enter: @TSeeeeee Where eeeeeee is

the email subject

(limited to 15 ASCII

characters)

Enter: @TD Dial up ISP and

complete email

transmission using

above data for email

accounts.

iNet AT® commands must be sent from the Host controller at

57600bps, N81 (no parity, 8 databits, 1 stop bit).

Note that the ISP Mail Server Address must be specified in

Hexadecimal. Refer to Cermetek Application Note #147, “Proce-

dure to convert user account address to Hexadecimal”.

Example: Over ride default pre-programmed ISP

account ID & Password, email destina

tion address, local access phone

number, send email.

Enter: @TLaaaaaa Where aaaaaa is ISP

account ID

Enter: @TPbbbbbb Where bbbbbb is ISP

account Password

Enter: @TOcccc Where cccc is ISP

mail server address

Enter: @TNdddddd Where dddddd is the

local ISP access

phone number

Enter: @TNaaaaaaa Where aaaaaaa is

the ISP local access

phone number

Enter: @TObbbbbb Where bbbbbb is the

email destination

address

Enter: @TD Dial-up ISP and send

email.

Changing the Default Internet Configuration Profile.

When various iNet AT® commands that modify internet configura-

tion parameters are issued to the iModem®, the changes invoked

by these commands are only temporary. Once power to the

iModem® is removed, the changes are lost. The default configu-

ration profile will not be lost when power is removed from the

iModem®.

Table 3. iModem® Family Pin Descriptions

Table 4. Pin Comparison of CH179X, HS Modem and CH21XX

iModem® Family

Example: Dial 9, pause, dial number.

Enter: ATDT9, T1234567

Multiple commas may be used for a greater delay time.

Touch Tone and Pause Dialing

The iModem® can use DTMF (touch-tones) “T”, or dial pulses “P”

when dialing a telephone number. If the dial command does not

specify which type to use, the modem defaults to the type last

specified. The power-on default value is T.

Example: Pulse dial 9, pause, touch-tone dial

number

Enter: ATDP9, T1234567

Redial Last Number.

Use A/, the repeat command, to redial the last telephone number

dialed when a busy signal is received.

Example: Touch-tone dial 9, pause, dial number,

return for command.

Enter: ATDP9, T1234567;

Return to Command State.

The iModem® can be forced to reenter the command state after

dialing (without hanging up) by ending the dial command with a

semi-colon. This is useful when using the modem as an auto

dialer.

Automatic Answering.

S0=0* DO NOT ANSWER TELEPHONE

S0=1-254 ANSWER ON RING 1 TO RING 254

S0=255 ANSWER ON RING 255

*When S0 is set to 0, the modem will not auto answer.

PROGRAMING THE iModem®

Cemetek’s iModem® requires an ISP (Internet Service Provider)

address, ISP account password, local PSTN dial up phone

number and valid email address to send and receive emails.

The required information can be modified by including it on the

appropriate iNet AT® Command line at the time the commands

are issued from the host processor.

Commands can be issued to the iModem® using any number of

commercially available terminal emulation programs - such as

PROCOM or HYPER TERMINAL. As an added service to our

customers, each iModem® is shipped from the factory with a

default ISP account and password for interim use. The default

PSTN dial up phone # is local to Sunnyvale, CA.

Pause During Dialing.

When placing a call from an office with a telephone connected to

a PBX, it may be necessary to dial an access code (usually the

digit 9) to get an outside line. Inserting a comma in the telephone

number commands the iModem® to pause for a specific length

of time. The factory default pause time is 2 seconds.

If a carrier is detected, the iModem® gives a CONNECT result

code and goes on-line, permitting communication with the distant

modem.

The Dial Command may also be issued without a telephone

number. ATD causes the iModem® to pick up the telephone line

without dialing a number.

NIP medoMi XX12HC YLIMAF medoMSHdnaX971HC YLIMAF

1GNIRGNIR

2PITPT

3IT1T

4CNTNES

5KPSKPS

6CNDNES

7CN1NI

8*NEPO2NI

9CNCN

01DXTDXT

11DXRDXR

21CNCN

31RTDRTD

41RSDRSD

51IRIR

61STCSTC

71DCDDCD

81CNCN

91V

02DNGDNG

12TSRTSR

22STRSTR

Table 5A Summary of Non-Extended Result Codes. Table 5B Extended Result Codes.

Note: 1. Am “x” in a column indicates that the message (either the long form if verbose, or the value only for short form) will be generated

when that particular value of “n” (shown at the top of the column) has been selected by the use of ATXn. A numeral indicates which less

explicit message (verbose or short form) will be output for that X option.

Table 5C. Extended Result Codes. Table 5C. Extended Result Codes.

esreT ro trohS

roesobreV gnoL 01234

56100023TCENNOCXXXXX

66100043TCENNOCXXXXX

76100063TCENNOCXXXXX

86100083TCENNOCXXXXX

96100004TCENNOCXXXXX

07100024TCENNOCXXXXX

17100044TCENNOCXXXXX

27100064TCENNOCXXXXX

37100084TCENNOCXXXXX

47100005TCENNOCXXXXX

57100025TCENNOCXXXXX

67100045TCENNOCXXXXX

77100065TCENNOCXXXXX

87100065TCENNOCXXXXX

971004032TCENNOCXXXXX

esreT ro trohS

roesobreV gnoL 01234

08100082TCENNOCXXXXX

18133392TCENNOC1XXXX

28176603TCENNOC1XXXX

38133333TCENNOC1XXXX

48176643TCENNOC1XXXX

58133373TCENNOC1XXXX

68176683TCENNOCXXXXX

78133314TCENNOCXXXXX

88176624TCENNOCXXXXX

98133354TCENNOCXXXXX

09176664TCENNOCXXXXX

19133394TCENNOCXXXXX

29177605TCENNOCXXXXX

39133335TCENNOCXXXXX

49177645TCENNOCXXXXX

Result Code Form n in ATXn Command Result Code Form n in ATXn Command

PHONE LINE CONNECTION GUIDELINES

1. The iModem® must be mounted in the final assembly such

thatit is isolated from exposure toanyhazardousvoltageswithin

theassembly. Adequate separation and restraintof cablesand

cords must be provided.

2. The circuitry from the iModem® to the telephone line interface

must be provided in wiring that carries no other circuitry other

than that specifically allowed in the FCC rules (such as A and

A1 leads).

3. Connection to phone line should be made through an RJ-11C

jack.

4. PCB traces from the modem’s RING and TIP pins to the

RJ-11C jack must be 0.1 inch spacing or greater to one

another and 0.2 inch spacing or greater to all other traces.

The traces should have a nominal width of 0.020 inches or

greater.

5. The RING and TIP PCB traces should be as short as possible

and oriented to prevent coupling other high speed or high fre-

quency signals present on the host circuit PCB.

6. No additional circuitry other than that shown in Figure 7 may

be connected between the modem module and the RJ-11C

Jack. Doing so will invalidate the FCC approval.

7. The iModem®, the RJ-11 Jack, the interfacing circuitry and all

PCB traces in between, must be contained on a PCB with a 94

V-0 flammability rating.

8. The supplied FCC registration label must be applied visibly on

the outside of the product.

9. The product’s User Manual must provide the user with instruc-

tionsfor connection and use asrecommended in theFCC Reg-

istration Section below.

CANADIAN APPROVALS

The iModem® family is approveable for use by DOT to CSA CS-

03 Part I. However, per Canadian procedures, approval can only

be granted after the iModem® has been installed into the end

product. Typically, Canadian approval is obtained by submitting

the final end product to an independent test house or consultant

for evaluation. The test house/consultant then forwards the test

results and applicable documents to the regulatory agency.

Cermetek offers a list of consultants to assist with this process.

iModem® HANDLING AND ASSEMBLY RECOMMENDATIONS

TheiModem®containsstatic-sensitivecomponents and should only

be handled by personnel and in areas that are properly protected

against static discharge.

FOR YOUR USER’S MANUAL

The part 68 rules require the following (or equivalent) be provided

to the end user of the equipment containing a DAA:

Type of Service: The (insert end product name) is designed to be

used on standard device telephone lines. It connects to the tele-

phone line by means of a standard jack called the USOC RJ-11C (or

USOC RJ45S). Connection to telephone-company-provided coin

service (central office implemented systems) is prohibited. Connec-

tion to party lines service is subject to state tariffs.

Changes in Attestation Procedure for Plugs and Jacks:

(Name of applicant) attests that the network interface plugs or

jacks used on this equipment comply with and will continue to

comply with the mechanical requirements specified in Part 68,

Sub-part F, specifically the dimensions, tolerances and metallic

plating requirements. The compliance of these connectors will be

assured by purchase specifications and incoming inspection.

Documentation of such specifications and/or inspections will be

provided by the FCC within 30 days of their request for the same.

Telephone Company Procedure: The goal of the telephone com-

pany 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 effect

your service or the operation of your equipment, the telephone com-

panywillgiveyou notice, in writing, to allow you to makeany changes

necessary to maintain uninterrupted service.

In certain circumstances, it may be necessary for the telephone

company to request information from you concerning the equip-

ment 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); both of these

items are listed on the equipment label.

There are two mounting techniques that are recommended for physi-

cally connecting the iModem® to a PCB:

1. Direct soldering

2. Sockets.

Direct Soldering.

TheiModem® may be wave soldered ontoacircuitcard. AlliModem®

products are hermetically sealed and will not be harmed by industry

standard wave soldering processes.

Socketing.

The socketing approach to mounting eliminates cleaning and

desoldering concerns. When the socket is used, it must make a

solid connection to all pins. Failure to do so will cause unreliable

or intermittent operation. Also, steps should be taken to assure

that the module remains tightly seated in the socket after the end

product is shipped. Cermetek recommends socket CES-150-01-T-

S by Samtec, 50 pin strip socket.

FCC REGISTRATION

All products in the iModem® family are registered with the FCC

under Part 68. To maintain the validity of the registration, you must

serve notice to the end user of the product of several restrictions

the FCC places on the modem and its use.

In addition to restriction notification, the FCC requires that

Cermetek make all repairs to all products in the iModem® family.

If repairs are necessary after installation of the iModem® and the

end product has been delivered to the end user, the end product

must be returned to the end product supplier where the iModem®

can be removed and then forwarded to Cermetek repair. The

following notice is recommended and should be included in the

end product’s user manual.

Figure 6. Schematic Illustrating Implementation of Voice

Injection Feature.

Table 6A. Summary of Basic AT Commands.

A/ Re-execute command

A Go off-hook and attempt to answer call

B0 Select V.22 connection at 1200bps

B1 Select Bell 212A connection at 1200bps

C1 Return OK message

Dn Dial modifier

P Pulse Dial

T Touch Tone Dial

W Wait for Dial Tone

; Return to Idle State

@ Wait for Quiet Answer

Command

! Flash Hook

, Pause

0-9/ABCD Dial Digits/

Characters & wait for credit

card dial tone

Ù Toggles calling tone

L Redial last number

* Star digit - tone dialing

S=n Dial the number and store in

directory. N 0 to 3.

E0 Turn off command echo

E1 Turn on command echo

H0 Initiate a hang-up sequence

H1 If on-hook, go off-hook and enter command

mode

L0 Set low speaker volume

L1 Set low speaker volume

L2 Set medium speaker volume

L3 Set high speaker volume

M0 Turn Speaker off

M1 Turn speaker on during hand shaking and turn

speaker off while receiving carrier

M2 Turn speaker on during hand shaking and while

receiving carrier

M3 Turn speaker off during dialing and receiving

carrier and turn speaker on during answering

N0 Turn off auto-mode detection

N1 Turn on auto-mode detection

O0 Go on-line

O1 Go on-line and initiate a retrain sequence

Q0 Allow result codes to DTE

Q1 Inhibit result codes to DTE

Sn Select S-Register as default

Sn? Return the value of S-Register n

Sn=v Set default S-Register to value v

V0 Report short form (terse) result codes

V1 Report long form (verbose) result codes

W0 Report DTE speed in EC model

W1 Report line speed, EC protocol and DTE speed

W2 Report DCE speed in EC mode

COMMAND FUNCTION COMMAND FUNCTION

X0 Report basic call progress result codes, i.e.