Novatel Wireless NRM-3800 Another Manual

AT Command Set

Reference Guide

for

Expedite and Merlin

Wireless IP Modems

PS-01016529

UNRELEASED

Release 2.1

Friday, May 7, 1999

The information disclosed herein is the exclusive property of NOVATEL WIRELESS TECHNOLOGIES LTD. and is not to be disclosed without the written consent of NOVATEL WIRELESS TECHNOLOGIES LTD. No part of this publication may be reproduced or transmitted in any form or by any means including electronic storage, reproduction, execution or transmission without the prior written consent of NOVATEL WIRELESS TECHNOLOGIES LTD. The recipient of this document, by its retention and use, agrees to respect the security status of the information contained herein.

This document is intended for limited circulation.

The information contained in this document is subject to change without notice and should not be construed as a commitment by NOVATEL WIRELESS TECHNOLOGIES LTD. unless such commitment is expressly given in a covering document.

REVISION HISTORY REV# ECO# EFF. DATE DESCRIPTION PREPARED APPROVED 1 99010 990505 Initial release.

2.0

99024 990705 Updated to include new features for

D. Barber S. Smilar

D. Barber S, Smilar TV01-02, including Friends Mode, Quiet mode and Stack Check features.

2.1

Added registration mode and out-of-

service sleep commands. Added index of AT commands.

NOVATEL WIRELESS TECHNOLOGIES LTD.

Table of Contents

INTRODUCTION.................................................................................................................................................... 6

Scope....................................................................................................................................................................... 6

PHYSICAL INTERFACE....................................................................................................................................... 7

Protocol................................................................................................................................................................ 7

Software Interface .................................................................................................................................................. 8

AT Command Mode........................................................................................................................................... 8

Command format................................................................................................................................................ 8

Result format....................................................................................................................................................... 8

Data Mode Description...................................................................................................................................... 9

Internal Stack Description ............................................................................................................................... 10

UDP Mode Description.................................................................................................................................... 11

TCP Mode Description..................................................................................................................................... 12

DTR Control Description.................................................................................................................................. 14

Push Technology.............................................................................................................................................. 15

Slip Mode........................................................................................................................................................... 16

Point to Point Protocol (PPP).......................................................................................................................... 17

Data Transmission Mode ................................................................................................................................18

Data Reception Mode...................................................................................................................................... 19

Sleep Mode Description................................................................................................................................... 20

Sleep Mode Feature Enable/Disable............................................................................................................. 21

Out-of-service Sleep Mode ............................................................................................................................. 22

Power-up Default Mode................................................................................................................................... 25

Set Hardware Configuration............................................................................................................................ 26

Profile Configuration Commands................................................................................................................... 27

Program Mode.................................................................................................................................................. 28

Local Echo......................................................................................................................................................... 29

Response Format............................................................................................................................................. 30

Programmable I/O............................................................................................................................................ 31

Soft Reset.......................................................................................................................................................... 33

Side Preference................................................................................................................................................ 34

Password........................................................................................................................................................... 35

Escape Sequence ............................................................................................................................................ 36

Hardware Flow Co ntrol.................................................................................................................................... 37

Disconnect (Hang-up)...................................................................................................................................... 38

Restore Factory Defaults................................................................................................................................. 39

Line Speed and Format................................................................................................................................... 40

View Active Profile............................................................................................................................................ 42

Save Current Profile......................................................................................................................................... 43

Destination IP Address/Port............................................................................................................................ 44

Debug Mode...................................................................................................................................................... 45

Auto Answer (TCP Listen)............................................................................................................................... 46

Connection Establishment Time-out.............................................................................................................. 47

Data Forwarding Idle Time-out....................................................................................................................... 48

Data Forwarding Idle Character ..................................................................................................................... 49

UDP Half Open Mode...................................................................................................................................... 50

Status Reporting............................................................................................................................................... 51

Local IP Address/Port...................................................................................................................................... 53

Service ID Preference...................................................................................................................................... 55

Channel Scan Mode......................................................................................................................................... 56

Channel List ...................................................................................................................................................... 58

AT Command Specification-Expedite and Merlin

Wireless IP Modems

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Service ID Preference...................................................................................................................................... 59

CDPD Operating Version ................................................................................................................................60

Wireline Compatibility ...................................................................................................................................... 61

Set DTR Control ............................................................................................................................................... 62

DTR Mode Setting............................................................................................................................................ 63

DSR Control Setting......................................................................................................................................... 64

TCP Timer......................................................................................................................................................... 65

Identity Registers.............................................................................................................................................. 66

Description:........................................................................................................................................................66

Query Network Connection Status................................................................................................................. 67

Last network registration error code.............................................................................................................. 70

Authentication Parameter................................................................................................................................71

Query Current RSSI Value.............................................................................................................................. 72

Query Current Block Error Rate (BLER) ....................................................................................................... 73

Current RF Channel in use ............................................................................................................................. 74

Cell Site ID in Use ............................................................................................................................... ............. 75

Area Color Code in Use................................................................................................................................... 76

Power Level Query........................................................................................................................................... 77

Symbol Error Rate Query................................................................................................................................78

Power Product................................................................................................................................................... 79

Authentication Failures Query......................................................................................................................... 80

Dial (Connection Setup)................................................................................................................................... 81

ADC Monitoring................................................................................................................................................. 83

Ping Command................................................................................................................................................. 86

Power Boost...................................................................................................................................................... 87

Message Waiting.............................................................................................................................................. 88

Internal MRU Setting........................................................................................................................................ 89

TCP Suspension Enable ................................................................................................................................. 90

Call Progress Result Mode ............................................................................................................................. 91

Answer............................................................................................................................................................... 92

Telnet Echo ....................................................................................................................................................... 93

Modem Identification........................................................................................................................................ 94

Friends Mode.................................................................................................................................................... 95

Stack Check...................................................................................................................................................... 97

Quiet Mode........................................................................................................................................................ 98

Registration Mode ............................................................................................................................................ 99

Fixed Parameters........................................................................................................................................... 100

Unsupported Commands .............................................................................................................................. 101

Unsupported Functions.................................................................................................................................. 101

Appendix A: AT Command Set Quick Reference....................................................................................... 102

Index of AT Commands..................................................................................................................................... 106

AT Command Specification-Expedite and Merlin

Wireless IP Modems

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INTRODUCTION

This document is intended to provide the serial AT Command Interface provided by Expedite Wireles s IP Modem for em bedded OEM applic ations. T he Expedite Wireless IP m odem provides a connection-oriented service so that existing OEM application protocols can be used. In addition, the capability to switch the unit to Serial-Line-Internet-Protocol (SLIP) or Point-to-Point-Protocol (PPP) modes are provided so that new protocols can be developed within the OEM application.

This document describes the Novatel Wireless Expedite Wireless IP Modem. The Expedite Wireless IP modem is an OEM-module designed for integration into a host product to provide wireless data comm unication capability via the CDPD (Cellular Digital Pack et Data) Network. It features internal TCP and UDP IP stac ks as well as SLIP and PPP protoc ols f or an exter nal s tac k and provisions for using “Sleep Mode” to extend the operating time of battery powered devices.

Scope

The scope of this document is limited to providing information on the various AT commands which can be used on Novatel CDPD products as well as a brief s ummar y of some of the standard AT commands which are not supported. Internal design is sues, detailed operating instructions and cost information is not included in this document.

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PHYSICAL INTERFACE

Protocol

CDPD System Specification Part 400 Version 1.1 (CDPD F orum Inc.) This is the protocol stack for the Expedite Wireless IP Modem:

To Host

Commun ication Dr iver

SLIP PPP

AT Interface

UDP TCP

Host OEM Application Layers

SNDCP

MDLP

CDPD Layers

MAC

Physical

The Expedite Wireless IP Modem does not support V.42 compression in SNDCP. The TCP/UDP interface is capable of supporting up to 3 sessions simultaneously The AT-command set described herein is derived from “CDPD Implementor Guidelines”, Release 1.1 contains a subset of the commands described in Part 2014 that are supported by the Novatel Expedite Wireless IP Modem. For the purposes of this specification, “NRM” refers to the Novatel Expedite Wireless IP Modem; “Host” refers to the OEM application controller.

This is provided to solve the problem presented by delays encountered when closing a TCP session. That is, in order to process

Host transactions in rapid succession (and si nce it is required to est ablish a new TCP session for each transaction) it is necessary to establish a new TCP session before the previous one has had a chance to close.

CDPD Forum makes no representations about the suitability of any material, comprising the CDPD system specification (or any

derivative work incorporating any element thereof) for any purpose; it being provided “as is” and without any warranties whatsoever, express or implied. The CDPD Forum shall not be responsible for any damages of any kind related to the use of the CDPD system specification (or any derivative work incorporating any element thereof), including without limitation, actual, direct, indirect, incidental, consequential, special, or general damages.

. It

AT Command Specification-Expedite and Merlin

Wireless IP Modems

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Software Interface

A brief description of those functions specific to the Expedite Wireless IP Modem is described here.

AT Command Mode

AT comm ands and responses ar e active in comm and mode only; as determ ined by the state of the DSR line. Command m ode behavior conform s to ANSI/TIA/EIA- 602-1992 section 5, with the limitations stated below. The AT comm and set is a subs et of the AT com mand s et defined in ANSI/TIA/EIA-602 and in the CDPD System Specification Part 2014 Version 1.1, section 4.

Command format

Note the following limitations:

- The termination character is fixed as CR (ASCII 13).

- Command line editing is supported (BS, ASCII 08 only).

- Command line repeats (A/) is not supported.

- The rules described below for buf fering and flow control also apply to comm and mode. The Host should not transmit a single AT com mand which exceeds the buffer length (256 char acters). In addition, the Host should wait until all responses associated with an AT comm and s tr ing have been received before issuing another AT command.

- Abortion of command-in-progress is not supported.

- Default command parameters are accepted for the last command on a command line only.

Result format

The format of result code responses is determined by the ATV command setting. In terse mode, the result code is sent as a s ingle ASCII character followed by a carriage return (ASCII 13) character. In verbose m ode, a descriptive text message is s ent followed by a carriage return. The following result codes are emitted by the NRM:

Terse mode

0 OK Command accepted. 1 CONNECT Connection established. 2 RING Network origination indication. 3 NO CARRIER Connection terminated, not established or command aborted. 4 ERROR Invalid command parameter /state (e.g. DTR must be active before AT D can be

5 NO SOCKETS No free TCP sockets within S7 seconds. 6 NO DIALTONE CDPD link not established. 7 BUSY Refused by destination or network, OR: Operation in progress. 8 NO ANSWER No response received from the destination within S7 seconds. 9 HELLO Issued at power on/reset.

Verbose mode Description of Command

accepted.)

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Data Mode Description

The modem contains an integrated T CP/IP protocol stack. It is acc essed via AT comm ands that put the modem into either a T CP or UDP data communications mode. If the application hos t contains a TCP/IP stack, PPP or SLIP can be used to transfer IP packets between the application host and the modem.

The Data Terminal Ready (DTR ) line is us ed by the modem as a qualif ier f or its operation in a data m ode, TCP, UDP, SLIP or PPP. The DTR line is to be asserted before entering a data mode to indicate to the modem that the host computer is available for oper ation. The DT R line is de- asser ted to term inate a data session. The modem will not sustain a data mode session without DTR being active. The us e of DTR can be overridden by setting register S211 to 1: the equivalent of asserting DTR permanently.

The DSR Signal is driven by the modem to indicate the ex istence of a data s ession. When the local host asserts DTR, the m odem will respond with the DSR signal to indicate that the modem has entered data mode. DSR is de-asserted to indicate that the modem has exited data mode.

The NRM provides Host and Network originated ac cess to the connection- oriented service us ing TCP/IP. Host origination is accomplished via the DIAL (ATDT) command. Upon successful completion of the DIAL command (i.e. CONNECT result code), the NRM switches to TCP-Data mode. DTR must be asserted prior to issuing the ATDT, ATDP, AT\ASLIP or AT\APPP. If this is not followed the modem will not engage the session in a manner where it can be sus tained. The NRM signals a network origination to the Host using the RING result code. Failure to have DTR asserted while in “Listen” mode, network origination, will result in a dropped session. The PAD f unctions are active during TCP-Data mode only, however, the data buffering functions apply in all modes.

For Listen mode applications, the modem must see DTR asserted when the TCP Session request is received. If DTR is not asserted the session request will be rejected. W hen the DT R signal is asserted, the modem will issue a RING followed by a CONNECT to indicate the beginning of an incoming data session. Here RING indicates the source of the session as being a remote server while the CONNECT indicates the transition from AT Command m ode to Data mode. . In this m ode, the NRM will “Listen” for TCPP packets with port num bers which match that s pecified with the NRM’s IP address (re: S110) . Any TCP packets rec eived in AT-CDPD mode, or pack ets re ceived in TCP-Data mode without a matching por t number, are rejected by the NRM with no indication to the Host. DTR can be used to terminate the session or the remote server can initiate the termination.

A session may be terminated by the Host de-asserting the DT R line. The remote hos t may also terminate a session. Connection status is maintained on the DSR line. Once the sess ion has been term inated, the NRM returns to AT-CDPD mode. Note that s ession term ination is the only m ethod to r eturn to AT -CDPD

mode For UDP/IP, a connection-oriented service is “fabricated” within the NRM. The DIAL com mand ( ATDP) is

used to place the NRM into UDP-Data mode. In this m ode, the NRM will “Listen” for UDP packets with port numbers which match that specified with the NRM’s IP address (re: S110). Any UDP packets received in AT-CDPD mode, or pack ets rec eived in UDP-Data m ode without a m atc hing port num ber, are rejected by the NRM with no indication to the Host. In UDP-Data mode, the port number for trans mitted UDP packets is specif ied with the destination address assoc iated with the DIAL command. O nly the Host Origination and Host Termination s cenarios des cribed above apply to UDP operation. The DT R and DSR lines, and the PAD functions, operate as in TCP-Data mode.

The Hayes compatible escape sequence is not supported.

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Wireless IP Modems

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Internal Stack Description

IP (Internet Protocol) is the basic network protocol that routes packets on an IP network . CDPD networks and the Internet are IP networks. Transport protocols deliver packets between applications. Transport protocols use the IP service to deliver data packets between network devices.

In order for an application to com municate across a network , it will first open a port on the local device. The IP address of the local device and this port number becomes the unique address for this application, and is sometimes referred to as a

socket

application, it will send a packet addressed to the IP addres s and port number of that rem ote application. This address is the destination address of the packet. The packet will also contain the source address, the IP address and port number of the local application. The remote application m ay use the source address of the packet received to communicate back to the local application. There are two common transport protocols used in TCP/IP networks:

. When the local application communicates with a distant

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UDP Mode Description

User Datagram Protocol is a basic transport protocol that provides a best-eff ort, connectionless delivery service with minimum overhead. The protocol does not guarantee delivery of packets. There is no checking or retransmiss ion of the data packets. It does provide minimum overhead as it only adds the source and destination port numbers to the header. Since the protoc ol is unreliable, the application m ust provide checking, ack nowledgments and retransmissions if the data is critical. In many applications, the data is not critical because updates are sent periodically and occasional losses can be tolerated.

UDP sessions may be originated by the local application host or by the network. T he asserted or session. The session is terminated by dropping DTR or resetting the unit.

S211=1

(pretend DTR is always asserted) for the unit to enter into a data comm unications

signal must be

DTR

UDP Modes of Operation

Command: ATS82 = <mode> Where <mode> = Timer value in seconds

0 = Regular mode 1 = Not used (reserved) 2 = Half-Open mode

Originating a UDP Session

A session is originated by the application host issuing the ATD (Dial) command:

ATDPnnn.nnn.nnn.nnn/ppppp

specifies a UDP session.

ATDP

destination application port number. If no port is spec ified then a por t num ber of 0 is ass um ed. It should be noted that UDP and TCP make ex tensive use of port number s, please be aware that the modem will use the port number as a criteria for accepting and passing data to the host application.

nnn.nnn.nnn.nnn

is the destination IP address and

ppppp

is the

CONNECT

assembled into a UDP packet and transmitted to the destination application.

ERROR

network.

PAD

occurs or when the PAD buffer is full. (256 or 512 bytes). T he idle time-out is spec ified in register 1/10 seconds.

Receiving Data

number specified in r egis ter link to the host application. Any packets received with a different port number specified will be discarded.

Termination -

[terse 1] result code will be issued and all ensuing data sent from the host application will be

[terse 4] result code will be generated if the modem is not currently registered on a CDPD

(Packet Assembly and Disassembly) function will transmit data when the inter-charac ter idle time-out

S50

- Once the session is started, any packets sent to the modem 's IP address with the port will be processed and the data portion will be transmitted over the s erial

S110

The session is terminated by dropping DTR or resetting the unit.

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TCP Mode Description

Transport Control Protocol, is a reliable, connection-oriented transport protocol that uses acknowledgments and retransmissions to guarantee delivery. This is an obvious advantage for applications where the data is critical and the application cannot provide the required reliability. There is more overhead in the protocol to provide this reliability, making it less eff icient than UDP. For larger data transfers, TCP is the easiest protocol to use to get reliable service.

TCP sessions may be originated by the local application host or by the network. The asserted or session. The session is terminated by powering the modem off, dropping DTR or by the remote host terminating the connection. If the s ession is terminated by a power down, the r emote host m ay not tear down its part of the session properly, leaving the remote host waiting for further information for that session. This can pose problems for some applications. Care in session tear down is essential for reliable operation.

S211=1

(pretend DTR is always asserted) for the unit to enter into a data comm unications

signal must be

DTR

TCP Modes of Operation

TCP Listen

will be used for the TCP Listen mode. The

S110

DTR pin and proceed as if DTR is always asserted) for the unit to enter into a data communications session. When a connection request for the correct port is received by the modem, the modem will establish the connection notify the local host with:

Verbose Terse RING 2 CONNECT 1

and begin the TCP session.

Termination -

connection terminating the session.

mode is established by having

A TCP connection is terminated by dropping DTR, or by the remote end of the TCP

when the modem powers up. . The port specified in

S0=1

signal must be asserted or

DTR

S211=1

(ignore signal on

Originating a TCP Session

A session is originated by the host application by issuing the ATD (Dial) command:

ATDTnnn.nnn.nnn.nnn/ppppp

specifies a TCP session.

ATDT

destination application port number. T he modem will attempt to establis h a c onnection with the des tination host. If it is successful, a app host will be assembled into a TCP packet and transmitted to the destination application.

ERROR

network.

Connection Failure

following:

- Wrong IP address or port number

- The destination device does not have a TCP Listen process open on the port specified.

- The destination host already has a connection established with another client on the specified port.

[terse 4] result code will be generated if the modem is not currently registered on a CDPD

CONNECT

will be signaled by a

AT Command Specification-Expedite and Merlin

nnn.nnn.nnn.nnn

[terse 1] result code will be issued and all ensuing data sent from the

BUSY

Wireless IP Modems

is the destination IP address and

[terse 7] result code, and may be caused by one of the

ppppp

is the

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- Connection failed to com plete within the time specif ied in register S7 (sec). Normal values are about 30 seconds, but is very dependent upon the application requirements. Many applications, which provide their own time-out for connection failure, will have this value set to 60+ seconds.

(Packet Assembly and Disassembly) function will transmit data when the inter-charac ter idle time-out

PAD

occurs or when the PAD buffer is full. (256 or 512 bytes). T he idle time-out is spec ified in register

S50

1/10 seconds.

Receiving Data

number specified in r egis ter

- Once the session is started, any packets sent to the modem 's IP address with the port will be processed and the data portion will be transmitted over the s erial

S110

link to the host application. Any packets received with a different port number specified will be discarded.

Termination -

A TCP connection is terminated by dropping DTR or by the remote end of the TCP

connection terminating the session.

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DTR Control Description

The DSR Signal is driven by the modem to indicate the existence of a data session. When DTR is asserted by the local host, the modem will respond with the DSR signal to indicate that the modem has entered data mode. DSR is de-asserted to indicate that the modem has exited data mode.

For Listen mode applications, the modem must see DTR asserted when the TCP Session request is received. If DTR is not asserted the session request will be rejected. W hen the DT R signal is asserted, the modem will issue a RING followed by a CONNECT to indicate the beginning of a incoming data session. Here RING indicates the source of the session as being a remote server while the CONNECT indicates the transition from AT Command m ode to Data mode. . In this m ode, the NRM will “Listen” for TCPP packets with port num bers which match that s pecified with the NRM’s IP address (re: S110) . Any TCP packets rec eived in AT-CDPD mode, or pack ets re ceived in TCP-Data mode without a matching por t number, are rejected by the NRM with no indication to the Host. DTR can be used to terminate the session or the remote server can initiate the termination.

A session may be terminated by the Host using the DTR line. T he remote host may also term inate a session. Connection status is m aintained on the DSR line. Once the session has been term inated, the NRM returns to AT-CDPD mode. Note that s ession term ination is the only m ethod to r eturn to AT -CDPD

mode The DTR line de-asserted can also be optionally used to power the modem off in addition to the

termination of the sess ion. If the S211 register is set to 4, then the de-ass erting of the DT R line will mak e the modem terminate any current data session, perform a de-registration with the network and power itself off.

The Hayes compatible escape sequence is not supported.

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Push Technology

To receive data while the modem is unattended by the host, the modem has been incorporated with the means to receive the data packet, determine the type of message and the source IP address. This push technology feature can be enabled or disabled by setting or resetting register S250. The modem can signal the host that there are messages queued up, waiting to be retrieved by the host, using any or all of the following signals. The “message waiting” signal can be asserted when a message arrives and will be de-asserted when all messages have been retrieved or deleted. In the case of multiple messages, the “message waiting” signal will be asserted when the first arrives and will only be de-asserted when all messages have been retrieved. Another signal, the “alert” signal, can also be used to provide a 500msec pulse to the host on its associated pin for each message that arrives. These signals can be made available on any of the programmable pins of the interface. Their assignment is made using the programmable GPIO features of the Expedite Wireless IP Modem.

The modem can hold up to 4 messages, determined by reading register S251, before the buffer overflows and message data is lost. When the host accesses the modem to retrieve the stored messages, the host first determines which messages it wants to retrieve based upon the source IP address. The host can discard messages by setting register S254. This will cause the current message to be flushed from the queue and the next message made available to the host.

PUSH Technology Enable ATS250? Query Wake Up Protocol State ATS250=1 Enable Push Technology

ATS250=0 Disable Push Technology ATS251? Query Number of Pending Messages

Response [0..4]

ATS252? Query First Push Message

Response [IPaddress/port] Format nnn.nnn.nnn.nnn/xxxxx

ATS253? Query Type of First Push Message Response [0, 1] 0 indicates UDP, 1 indicates TCP

ATS254=1 Discard Current Message

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Slip Mode

Description:

The command to enter Serial Line Internet Protocol mode (SLIP) is used when an external stack configuration is needed. SLIP is useful if the stack resides in the host com puter, multiple sessions and complete control over all aspects of each session can be obtained. SLIP is one of the more comm on protocols used for splitting the functionality between the modem and the host. SLIP does, however, require certain parameters to be s et up prior to ac tivating a ses s ion. SLIP does not ex tr act the IP addr es s from the m odem. This must be set up in dial-up-network ing before starting. SLIP is less flexible than Point to Point Protocol (PPP) which is quickly winning over most users.

The SLIP session is usually controlled by DTR, unless the m odem has been configured to ignore DTR by programming register S211. DT R, when used, must be asserted to initiate a s ession and de-asserted to terminate a session. If the m odem has been programmed not to use DT R Control, then the command AT\ASLIP can be sent without asserting DTR. T o exit SLIP in this case, the hos t m us t either power down the modem or use the es cape sequence. To term inate a SLIP session, DT R must be de-asserted or the escape sequence can be activated or the modem can be powered down.

Format:

AT\ASLIP The command to enter SLIP mode

Validity:

Slip can only be entered from Command Mode. In Program or Diagnostic modes, the modem is not actively connected to the network.

Other Considerations:

While a modem can enter SLIP mode from command mode at any time, the intent of SLIP is to connect to the network. Until there is a network connection es tablished and the m odem has regis tered, it is better to delay entering SLIP mode as you may report errors that will only persist until the modem register s. It is generally recommended that the host check the status of the modem before proceeding with a SLIP connection. The Status can be checked using the “ATS57?” command.

Related Topics:

Enter PPP Mode, DTR Control, Program Mode, Data Mode, Diagnos tic Mode. Checking Status, Escape Sequence

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Point to Point Protocol (PPP)

Description:

The command to enter Point to Point Protocol mode (PPP) is used when an external stack configuration is needed. PPP is useful if the stack resides in the hos t c omputer, providing multiple ses s ions and c omplete control over all aspects of each session. PPP is quickly becoming the new standard for dial-in-networking. PPP provides more flexibility and less items that need to be explicitly set.

The PPP session is usually controlled by DTR, unless the modem has been conf igured to ignore DTR by programming register S211. DT R, when used, must be asserted to initiate a s ession and de-asserted to terminate a session. If the m odem has been programmed not to use DT R Control, then the command AT\APPP can be sent without asserting DTR. To exit PPP in this case, the host m ust either power down the modem or use the es cape sequence. To term inate a PPP session, DTR must be de-asserted or the escape sequence can be activated or the modem can be powered down. .

Format:

AT\APPP The command to enter PPP Mode The response will be CONNECT or ERROR The alternate command to use is SERVER The response will be CLIENT

Validity:

PPP can only be entered from Comm and Mode. In Program or Diagnostic modes, the m odem is not actively connected to the network.

Other Considerations:

While a modem c an enter PPP m ode fr om com m and m ode at any time, the intent of PPP is to c onnect to the network. Until there is a network connection es tablished and the m odem has regis tered, it is better to delay entering PPP mode as you may report errors that will only persist until the modem r egisters. It is generally recommended that the host check the status of the modem before proceeding with a PPP connection. The Status can be checked using the “ATS57?” command.

An alternate method of entering PPP m ode is to send the word CLIENT to the m odem. The m odem will respond with SERVER. This is NOT an AT comm and. It is neither preceded by an "AT " nor succ eeded by a CR. Exiting PPP mode is performed using the DTR control signal.

Related Topics:

SLIP Mode, DTR Control, Program Mode, Data Mode, Diagnostic Mode. Checking Status

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Data Transmission Mode

Packet Assembly

The NRM provides a local Packet Assembly and Disassem bly (PAD) function. For transm ission,

the character stream from the Host is assembled into packets for RF transmission under the

following conditions:

-Idle time-out: If the time between succ essive characters exceeds the time inter val specified in

Buffering and Flow Control

The NRM has an input data buffer which is intended to be set larger than the longest trans mit

message used by existing protocols in the Host. The size of this buffer is 578 characters.

If hardware flow control is disabled and, the NRM is formatting and transmitting data blocks

associated with a packet, the Host should not send additional data as this m ay cause input buff er

overflow. Buffer overflow will result in a loss of data with no indication to the Host. In order to

avoid data loss, it is recomm ended (and anticipated) that the Host application protocol operates

using a half-duplex ACK/NAK protocol. It should be expected that the Host acknowledgment

time-out should be set greater than that requir ed for circuit-s witched m odem configurations . T his

is to account for propagation delays through the NRM, CDPD base station and CDPD and Internet

networks.

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Data Reception Mode

Packet Disassembly

The NRM begins transmitting the character stream ass ociated with a received packet to the Host

as soon as all the associated blocks have been received and processed.

Buffering and Flow Control

The NRM has an output data buffer which is intended to be set larger than the longest receive

message used by existing protocols in the Host application. The size of this buffer is 2144

characters.

When the NRM is sending the characters associated with a received packet to the Host, the

remote host processor should not send additional data as this may result in output buffer overflow.

NRM buffer overflow shall result in a los s of data with no indication to the Host or rem ote hos t. In

order to avoid data loss, it is recom mended (and anticipated) that the Host application protoc ol

operates using a half-duplex ACK/NAK protocol. The remote host acknowledgment time-out

should be lengthened as described above.

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Sleep Mode Description

Sleep mode can be activated by sending the comm ands AT#ZZ=1, AT#ZZ=2 or deactivated by

the command AT#ZZ=0. Changes must be entered in program mode. The module should be

reset after changing the sleep mode ac tivation s ince the module will have registered and inform ed

the network that it has sleep mode or not. The module will enter sleep mode, if ac tivated, af ter the

inactivity timer has expired and a Network TEI notification message has been received by the

modem.

In areas with low signal strength or where the signal strength varies to a high degree, the unit ma y

not enter sleep mode in a regular fashion. The unit must have conditions where the unit can

decode the TEI notification messages from a reliable signal.

No notification message or signal is given to the host that sleep m ode is engaged. The hos t mus t

assume that if the modem has been inactive for more than the number of seconds specified in the

inactivity timer that the modem has gone to sleep.

To wake the modem up from s leep mode, the wake-up signal can be as serted for a m inimum of

10 ms or a break character of 20 ms in duration followed by a 2 ms pause or 2 c haracter spaces

at 19200 bps can be sent. The module will de-assert CTS when entering sleep mode to inhibit the

host from sending data but will periodically assert CTS and check for incoming serial data from

the host to prevent any loss of data.

No indication is given to the module that the host is in sleep mode. T he module will ass ume the

host is sleeping if the module is sleeping and send a break char acter to initialize comm unications

with the host.

There are two types of sleep mode implemented for this product:

i. Normal – in normal s leep mode, the modem will attem pt to maximize its s leep time based

on the configuration of the network where it has r egistered. Practically, this means that if the network supports a sleep time of 60 seconds, and allows 5 TEI notifications to be missed without penalty, the modem could theoretically sleep for a minimum of 4 minutes.

ii. Short – in short sleep mode, the modem will attem pt to sleep in s hort bursts of 5 s econds

and awaken to allow communic ation from the hos t. In this mode, CT S would normally be deasserted so hosts would not normally attempt to send data until the CT S is asserted again in 5 seconds when the modem wakes up for 400m sec. This is the s ame operation as in the NRM6812 products when AT#ZZ=2 and has been maintained for backward compatibility.

Related Topics:

Sleep Mode Feature Enable/Disable

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Sleep Mode Feature Enable/Disable

Description:

This command permits the user to define what sleep mode the modem should use. Since various applications and host computers have different requirements for communicating with a modem that utilizes sleep mode, this command encompasses several different options that should satisfy any application. If sleep mode does not appear to work with your application, please contac t Novatel Wireless for assistance. The default setting for this mode is off.

Format:

AT#ZZ? Sleep status query command

AT#ZZ=0 Disable sleep feature

AT#ZZ=1 Enable Long cycle sleep

AT#ZZ=2 Enable short cycle sleep

Validity:

Changes must be entered in program mode.

Other Considerations:

See the sleep mode description.

Related Topics:

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Out-of-service Sleep Mode

The modem m ust be registered and within a reliable coverage area before it c an actually go to

sleep for standard sleep mode. This means that the m odem cannot sleep and will be in a higher

battery discharge state at all times that the modem is outs ide of CDPD coverage. The Out-of-

service Sleep Mode allows the modem to go to sleep dur ing periods of no c over age. The modem

will sleep for some (usually relatively long) period and wake occasionally to see if it has returned

to a coverage area. The goal is to give the modem a battery life approaching that of standard

sleep mode when within CDPD coverage.

Out-of-service sleep m ode is activated by sending the AT#NSZZ=1 comm and or deactivated by

sending the AT#NSZZ=0 com mand. This change must be saved with the AT&W co mm and, and

the module must be reset before this change will take effect.

Following a loss of signal, the modem will make s everal attempts to find servic e on the currently

registered side before deciding that it is no longer registered and that it must s ear ch both s ides f or

service. Once this has occurred, or following modem initialization under no service conditions, the

modem will continue to search for a valid CDPD signal f or the c omplete scan period. If no servic e

is found the modem will sleep for the sleep cycle length less the time that it was awak e for the

search. After this sleep interval, the m odem will wake for a br ief searc h. If no ser vice is found, it

will sleep again for the sleep cycle length less the brief scan per iod. T his c ycle continues with one

scan period in each cycle count periods being a complete scan. If the m odem finds s ervice and

registers during one of the scans, the out-of-service sleep mec hanism is reset and waits for the

next time that service is lost.

To prematurely wake the modem up from out-of -service sleep mode, the wake-up signal can be

asserted for a m inimum of 10 ms. The m odule will de-assert CT S when entering sleep mode to

inhibit the host from sending data but will periodically assert CTS and check for incoming serial

data from the host to prevent any loss of data.

Description:

These commands permit the user to define what the parameters of out-of-service sleep mode and to enable or disable the operation of this mode. If out-of-ser vice sleep mode does not appear to work with your application, please contact Novatel Wireless for assistance. The default setting for this mode is off.

Format:

AT#NSZZ Out-of-service Sleep status query command

AT#NSZZ=0 Disable out-of-service sleep feature

AT#NSZZ=1 Enable out-of-service sleep feature

AT#NSZZTM=p,b,c,n Configure out-of-service sleep feature

p = sleep cycle length in seconds. This is the interval between successive wakeups. b = brief scan period in seconds. This is the time that the modem will be awake for most of its waking intervals. It is intended to be a brief look at the hot list of the preferred side.

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Validity:

Changes must be entered in program mode.

Other Considerations:

Power-up Default Mode

Description:

The power up default mode com mand permits the us er to define how the modem will ac t after power is applied and the modem begins operating. Upon power up, the modem will perform a quick self test, determine its configuration and then enter the progr ammed default m ode. This can be either the standard AT Command mode or PPP, SLIP or UDP data modes.

The use of PPP or SLIP as the default mode perm its the user to eliminate the start up comm ands and hence have the unit register and activate the data mode m ore quickly. Since there is no requirement f or data exchange to set up SLIP, the host can proceed to set up its stack once the CONNECT message is received from the modem . Because PPP requires some data to be exc hanged to set up the IP and other parameters, the host must complete the PPP link before data can be sent or received.

The use of UDP as a default mode perm its a host to begin sending or receiving data over the modem connection as soon as the modem has registered on the network. T he m odem will power up, perform the quick self test, determine its configuration, enter AT Command mode and then, once the modem has registered on the network, enter UDP mode. Upon entering UDP mode a “CONNECT” message is sent to the host. The UDP mode can make use of the half-open or standard UDP features.

Format:

ATMD0 For AT Command mode at power-up

ATMD1 For SLIP Data mode at power-up

ATMD2 For PPP Data mode at power-up

ATMD3 For UDP Data mode at power-up

ATMD83 UDP with no IP address verify on incoming packets

Validity:

Power-up default mode changes can be m ade at anytime. Default modes were introduced in software release on September 97 and are valid for all later software revisions.

Other Considerations:

Because the default mode tak es ef fec t once the m odem has r egistered with the network , it is im portant to make any desired changes as soon after power up as possible.

Related Topics:

UDP, Enter PPP Mode, Enter SLIP Mode, AT Command Mode

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Set Hardware Configuration

Command to set the hardware release version number, i.e. Rev 3.2, Rev 3.3, Rev SM-1 etc.. The hardware configuration setting is set at the factory and should not normally be set by the user. The hardware configuration version can only be set in Diagnostic mode.

ATI3 Query Hardware configuration

AT#NH=number Set Hardware configuration

AT#NH? Query Hardware configuration

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Profile Configuration Commands

Description:

Upon power-on/reset, the NRM issues a HELLO (verbose) or a 9 (terse) result code and proceeds to register with the CDPD system. AT com mands are active by default. This state is referred to as AT- CDPD mode.

These commands affect settings that are stored in the modems Non-Volatile Memory (NVM). These commands are used by service personnel when the unit is ins talled and as required thereafter to update service access information. Note that some configuration changes will not be permanently saved until they have been written to Non-Volatile Memory (NVM) with the AT&W command.

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Program Mode

Description:

Program mode permits the user to change S register parameters that affect the modems operation. Program mode was c reated as a means of protecting the configuration of the modem from spurious or unwanted attempts to change them. The addition of the password protects the equipment from unauthorized access and modification. While in program mode, the modem is disconnected from the network. Data cannot be sent or received over the wireless link.

Format:

AT\APROG,NRM6812 Enter program mode

AT&W Save changes and exit program mode

ATZ Exit without saving changes

The password field is case sensitive

different. In the above example, NRM6812 is the default password. NRM must be entered as capital letters otherwise the password will not be accepted. Passwords should be more than six characters however the software will accept any number of characters up to 8.

. The modem will distinguish upper and lower case letters to be

Validity:

The user can enter program mode while in AT Command mode.

Other Considerations:

Besides being used as the password for entry into Program mode, the password is also used as a qualifier for the escape sequence used to exit data modes. Care should be used when changing passwords.

Related Topics:

Changing Password, Saving Settings, Soft Reset, S Registers,

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Local Echo

Description:

The Set Local Echo comm and perm its the user to select whether the m odem should echo the char acters sent to it back to the host. For some applications, local echo is not required as the hos t does not need to confirm what has been sent to the modem. For terminal operation, loc al echo can be used to verify what has been sent to the modem and aids in sending comm ands, since each keystroke is displayed on the terminal.

Format:

ATE0 Disable Local Echo

ATE1 Enable Local echo

Validity:

Changes to the local echo setting are valid during program or AT com mand modes. Changes made while not in program mode will be lost upon power down. Changes made and s aved while in program mode will be retained by the modem.

Other Considerations:

For a wide variety of applications, local echo is not required or desir ed. When using local echo with a terminal, it is wise to keep in mind that the application being used may require local echo to be off rather than on. Always ensure that the echo setting is set in the proper mode for the application when reinstalling a modem.

Related Topics:

Saving Settings, AT Command Mode

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Response Format

Description:

The Set Response Format comm and is used to def ine what manner the m odem returns when com m ands are sent to it. Responses can be defined to be either plain text messages or a single numeric digit. Numeric control is better suited for machine applications while plain text is better for interpretation by humans.

Terse mode

Verbose mode (Plain Text)

Description of Response

accepted.)

Format:

ATV0 To enable the response to be in the numeric format

ATV1 To enable the response to be in plain text

Validity:

Changes to the Response Format s etting are valid during program or AT com mand modes. Changes made while not in program mode will be lost upon power down. Changes made and saved while in program mode will be retained by the modem.

Other Considerations:

Some machine applications use the plain text response as it saves reformatting the information for presentation to a human operator.

Related Topics:

Saving Settings, AT Command Mode

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+ 76 hidden pages

Novatel Wireless NRM-3800 Another Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

INTRODUCTION

Scope

PHYSICAL INTERFACE

Protocol

Software Interface

AT Command Mode

Command format

Result format

Data Mode Description

Internal Stack Description

UDP Mode Description

UDP Modes of Operation

Originating a UDP Session

TCP Mode Description

TCP Modes of Operation

Originating a TCP Session

DTR Control Description

Push Technology

Slip Mode

Point to Point Protocol (PPP)

Data Transmission Mode

Packet Assembly

Buffering and Flow Control

Data Reception Mode

Packet Disassembly

Buffering and Flow Control

Sleep Mode Description

Sleep Mode Feature Enable/Disable

Out-of-service Sleep Mode

Power-up Default Mode

Set Hardware Configuration

Profile Configuration Commands

Program Mode

Local Echo

Response Format