Black Box MD278A, MD278A-R2, MD278C User Manual

To order or for technical support: Call 724-746-5500 or fax 724-746-0746 Technical support and fax orders 24 hours a day, 7 days a week Phone orders 24 hours, 7 A.M. Monday to midnight Friday; Saturday 8 to 4 (Eastern) Mail order: Black Box Corporation, 1000 Park Drive, Lawrence, PA 15055-1018

CUSTOMER

SUPPORT

INFORMATION

FEBRUARY 1998

MD278A

MD278A-R2

MD278C

Modem 325

Modem 325 Card

YES

TALKDATA

Modem 325

FEDERAL COMMUNICATIONS COMMISSION

AND

CANADIAN DEPARTMENT OF COMMUNICATIONS

RADIO FREQUENCY INTERFERENCE STATEMENTS

This equipment generates, uses, and can radiate radio frequency energy and if not installed and used properly, that is, in strict accordance with the manufacturer’s instructions, may cause interference to radio communication. It has been tested and found to comply with the limits for a Class A computing device in accordance with the specifications in Subpart J of Part 15 of FCC rules, which are designed to provide reasonable protection against such interference when the equipment is operated in a commercial environment. Operation of this equipment in a residential area is likely to cause interference, in which case the user at his own expense will be required to take whatever measures may be necessary to correct the interference.

Changes or modifications not expressly approved by the party responsible for compliance could void the user’s authority to operate the equipment.

This digital apparatus does not exceed the Class A limits for radio noise emission from digital apparatus set out in the Radio Interference Regulation of the Canadian Department of Communications.

Le présent appareil numérique n’émet pas de bruits radioélectriques dépassant les limites applicables aux appareils numériques de classe A prescrites dans le Règlement sur le brouillage radioélectrique publié par le ministère des Communications du Canada.

INSTRUCCIONES DE SEGURIDAD (Normas Oficiales Mexicanas Electrical Safety Statement)

1. Todas las instrucciones de seguridad y operación deberán ser leídas antes de que el aparato eléctrico sea operado.

2. Las instrucciones de seguridad y operación deberán ser guardadas para referencia futura.

3. Todas las advertencias en el aparato eléctrico y en sus instrucciones de operación deben ser respetadas.

4. Todas las instrucciones de operación y uso deben ser seguidas.

5. El aparato eléctrico no deberá ser usado cerca del agua—por ejemplo, cerca de la tina de baño, lavabo, sótano mojado o cerca de una alberca, etc.

6. El aparato eléctrico debe ser usado únicamente con carritos o pedestales que sean recomendados por el fabricante.

7. El aparato eléctrico debe ser montado a la pared o al techo sólo como sea recomendado por el fabricante.

8. Servicio—El usuario no debe intentar dar servicio al equipo eléctrico más allá a lo descrito en las instrucciones de operación. Todo otro servicio deberá ser referido a personal de servicio calificado.

9. El aparato eléctrico debe ser situado de tal manera que su posición no interfiera su uso. La colocación del aparato eléctrico sobre una cama, sofá, alfombra o superficie similar puede bloquea la ventilación, no se debe colocar en libreros o gabinetes que impidan el flujo de aire por los orificios de ventilación.

10. El equipo eléctrico deber ser situado fuera del alcance de fuentes de calor como radiadores, registros de calor, estufas u otros aparatos (incluyendo amplificadores) que producen calor.

11. El aparato eléctrico deberá ser connectado a una fuente de poder sólo del tipo descrito en el instructivo de operación, o como se indique en el aparato.

12. Precaución debe ser tomada de tal manera que la tierra fisica y la polarización del equipo no sea eliminada.

13. Los cables de la fuente de poder deben ser guiados de tal manera que no sean pisados ni pellizcados por objetos colocados sobre o contra ellos, poniendo particular atención a los contactos y receptáculos donde salen del aparato.

14. El equipo eléctrico debe ser limpiado únicamente de acuerdo a las recomendaciones del fabricante.

15. En caso de existir, una antena externa deberá ser localizada lejos de las lineas de energia.

16. El cable de corriente deberá ser desconectado del cuando el equipo no sea usado por un largo periodo de tiempo.

17. Cuidado debe ser tomado de tal manera que objectos liquidos no sean derramados sobre la cubierta u orificios de ventilación.

18. Servicio por personal calificado deberá ser provisto cuando:

A: El cable de poder o el contacto ha sido dañado; u B: Objectos han caído o líquido ha sido derramado

dentro del aparato; o C: El aparato ha sido expuesto a la lluvia; o D: El aparato parece no operar normalmente o

muestra un cambio en su desempeño; o E: El aparato ha sido tirado o su cubierta ha sido

dañada.

MODEM 325 AND MODEM 325 CARD

TRADEMARKS

Other product names mentioned in this manual may be trademarks or registered trademarks of their respective companies and are hereby acknowledged.

CONTENTS

1. Specifications. . . .......................................................14

2. Introduction . . . .......................................................15

2.1 General . . . .......................................................15

2.2 Description . . . . . . . . . . . . . ..........................................15

2.2.1 Functional. . . . . . . . . . ..........................................15

2.2.2 Physical. . . . . .................................................15

2.3 How to Use this Manual .............................................17

2.3.1 Specifications . . . . .............................................17

2.3.2 Option Selection. . . . ...........................................17

2.3.3 Quick Startup. . . . .............................................17

3. Installation . . . . . . . . . . . ................................................18

3.1 General . . . .......................................................18

3.2 Site Selection. . . . . .................................................18

3.2.1 Tools Required. . . . . . . . . . . . . . . . . . . . . . . . . . . .....................18

3.2.2 Receipt Inspection .............................................18

3.3 Electrical Installation . . . . ...........................................18

AC Power Connection . . . . ...........................................19

3.4 DTE Connection. ..................................................19

3.5 Telephone Cables . . . . . . ............................................23

3.6 Telephone Line Connection..........................................24

3.6.1 PSTN Connection .............................................24

3.6.2 Permissive. . . . . . . . . . ..........................................24

3.6.3 Programmable . . . . . . . . . . . . . . . . . . . . . . . . . . . .....................24

3.6.4 Leased-Line Connection . . . . . . ..................................26

4. Option Selection . . . . . . . . . . . . . ..........................................28

4.1 General . . . .......................................................28

4.2 Strap Option Selection . . . . ..........................................28

Removing Cover . ..................................................28

4.3 Hardware Straps. ..................................................31

4.3.1 Tip and Ring Polarity ..........................................31

4.3.2 Ground Option Strap ..........................................31

4.3.3 QM Disable Option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .........32

4.4 LCD Option Selection . . . . ..........................................32

4.5 Main Menu . . . . . . . . . . . . . ..........................................32

Menu Sequence . . . . . . . . . . ..........................................32

4.6 Option Selection . ..................................................40

4.6.1 Main Menu. ..................................................40

4.6.2 Submenu . . . . . . . . . . ..........................................40

4.6.3 Submenu Item . . . . . . . . . . . . . . . . . . . . . . . . . . . .....................40

4.6.4 Item Option . . . . . . ............................................41

4.6.5 Selecting the Option . ..........................................41

5. Operation . . . . . . . . . ...................................................42

5.1 General . . . .......................................................42

5.2 Controls and Indicators .............................................42

5.3 LED Descriptions . . . . . . ............................................42

5.3.1 Request to Send . . . . ...........................................42

5.3.2 Clear to Send . . . . .............................................42

5.3.3 Quality Monitor . . . . ...........................................42

MODEM 325 AND MODEM 325 CARD

5.3.4 Carrier Detect . . . . ............................................42

5.3.5 Received Data. . . . . . . ..........................................42

5.3.6 Transmit Data. . . . . . . ..........................................42

5.4 Getting on Line Quickly. . . ..........................................42

5.4.1 Manual Dialing. . . . ............................................43

5.4.2 Manual Answering . . . ..........................................43

5.4.3 Autodial (Front Panel) . . . .......................................43

5.4.4 AT Command Dialing . . . .......................................43

5.4.5 Software Communication Packages................................43

5.5 Error Control . . . . . . . ..............................................43

5.6 Flow Control . . ....................................................44

5.7 Autobaud . . . . ....................................................44

5.8 4-Wire Operation . . . . . . . . . . . .......................................44

5.9 2-Wire Operation . . . . . . . . . . . .......................................44

5.9.1 2-Wire Leased-Line Operation ...................................44

5.9.2 2-Wire Dial-Up Operation . . . . . . .................................45

5.10 Remote Configuration. . . . . . . .......................................45

5.11 Secure Operation. . . . . . . . . . . .......................................45

5.11.1 Operating Without Security . . . . . . ..............................46

5.11.2 Operating With Security . . . . . . .................................46

5.11.3 Remote Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .........46

5.11.4 Local Operation . . . . . . . .......................................46

5.11.5 Passwords . . . . . . .............................................46

5.11.6 LCD Indication of Security . . . . . . ...............................46

5.11.7 Security Reset. . . . ............................................47

5.11.8 Security Commands. . . . . . . . . . . . . . . . . . . . . ......................47

5.11.9 Restrictions in Security Operation................................47

5.12 Dial Backup . . . . . . . ..............................................48

5.13 Placing a Call . . ..................................................48

5.13.1 Direct Connect with a Standard Telephone ........................48

5.13.2 Direct Connect with an Exclusion-Key Telephone . . . ................49

5.13.3 Autodial from Front Panel. . ....................................49

5.13.4 Autodial with the AT Command Set ..............................49

5.14 Answering a Call. . . . . . . . . . . .......................................49

5.14.1 Autoanswer. . . . . . . . . . . .......................................49

5.14.2 Manual Answer . . . . . . . .......................................49

5.15 Call Termination. . . . . . . . . . . .......................................50

5.15.1 Conditions That Terminate a Call ................................50

5.15.2 V.32 Cleardown . . . . . . . .......................................50

6. Asynchronous Operating Commands . . ....................................51

6.1 General . . . . . . ....................................................51

6.2 Command Categories. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

6.3 Operation Modes . . . . . . . . . . . .......................................51

6.3.1 Offline Command Mode . . . . ....................................51

6.3.2 Online Command Mode . . . . ....................................52

6.3.3 Data Mode . . . . . . .............................................52

6.4 Sending Commands to the Modem . . . . . . ..............................52

6.4.1 Creating a Command Statement ..................................52

6.4.2 Autobaud . . ..................................................53

6.4.3 Guidelines for Creating Command Statements ......................53

6.4.4 Monitor Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

CONTENTS

6.4.5 Command-Statement Buffer . . . . . . ...............................53

6.4.6 Backspace Key . . . . . . . . . . . . . . . . . . . . . . . . . . . .....................53

6.4.7 Repeating a Command (A/) . . . . . . ................................54

6.4.8 Numbered Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

6.4.9 Group Commands .............................................54

6.5 Command Table. ..................................................55

6.6 Response Commands . . . . ...........................................59

6.6.1 How Response Messages Work ...................................59

6.6.2 Selecting Response Form (V). . . . . . ...............................59

6.6.3 Electing to Use Response Messages................................59

6.6.4 Enabled/Disabled Response Displays (Q) ...........................59

6.6.5 Dial Parameter and Connect Speed Displays (X) .....................60

6.6.6 Number Code Application (*RC) .................................61

6.6.7 Response Number Codes/Messages................................62

6.7 Dial Commands . ..................................................63

6.7.1 Dialing (D) . ..................................................63

6.7.2 Tone Dialing (T). . . . ...........................................64

6.7.3 Pulse Dialing (P). . . . ...........................................64

6.7.4 Insert Pause (,) . . . . . . . . . . . . . . . . . . . . . . . . . . . .....................64

6.7.5 Wait for Second Dial Tone (W) ...................................64

6.7.6 Switch Hook (!). . . . . . . . . . . . . . . . . . . . . . . . . . . .....................64

6.7.7 Switching to Answer Mode After Dialing (R) ........................64

6.7.8 Wait for 5 Seconds of Silence (@) .................................64

6.7.9 Remaining in Command Mode (;).................................65

6.7.10 Dialing a Stored Telephone Command Line (S) .....................65

6.7.11 Voice Calls . ..................................................65

6.7.12 Switch from Voice to Data. . . . . . .................................65

6.8 Answering a Call. ..................................................66

6.8.1 Manual Answer . . . . ...........................................66

6.8.2 AT Command Answer (A) . . . . . . .................................66

6.8.3 Autoanswer (S0) . . . . ...........................................66

6.9 Terminal-Interface Commands . . . . . . .................................66

6.9.1 Data Carrier Detect (&C). . . . . . ..................................67

6.9.2 Data Set Ready (&S). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .........67

6.9.3 Data Terminal Ready (&D) . . . . . . ................................68

6.9.4 Serial Port Ring Indicate (\R) . . . . . . ..............................68

6.9.5 Request to Send/Clear to Send (&R) ...............................69

6.9.6 DTE Fallback (Pin 23) (*FB) . . . . . . ...............................69

6.10 Test Commands (&T) . . . . ..........................................70

6.10.1 Bilateral Test Enable/Disable (*AN, *DG) ..........................71

6.10.2 DTE-Controlled Remote Digital Loopback (Pin 21) (*RD) ............71

6.10.3 DTE-Controlled Local Analog Loopback (Pin 18) (*LA) ..............71

6.11 General Commands . . . . ...........................................72

6.11.1 Changing from Data Mode to Command Mode (+++) ..............72

6.11.2 Local Character Echo (E). . . . . . .................................72

6.11.3 Hanging Up (H). . . . ..........................................73

6.11.4 V.32 Cleardown (H2, H3) . . . . . . ................................73

6.11.5 EPROM Check (I) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .........73

6.11.6 Speaker Volume (L) . ..........................................74

6.11.7 Speaker Control (M) ..........................................74

6.11.8 Return Online (O) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .........74

6.11.9 Long-Space Disconnect (Y) . . . . . . ...............................75

6.11.10 Guard Tones (&G). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .........75

MODEM 325 AND MODEM 325 CARD

6.11.11 Dial/Leased Line (&L).........................................76

6.11.12 Asynchronous/Synchronous Mode Selection (&M) ..................76

6.11.13 Make/Break Dial Pulse Ratio (&P) ...............................77

6.11.14 Synchronous Transmit Clock Source (&X) ........................77

6.11.15 DCE Speed (%B) . . . ..........................................77

6.11.16 Disconnect Buffer Delay (%D) ..................................78

6.11.17 Auto Retrain (%E) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .........79

6.11.18 Product Revision Level (%V) ...................................79

6.11.19 Product Serial Number ($V). . . . . . ..............................79

6.11.20 Permissive/Programmable (%Z) .................................79

6.11.21 Talk/Data (*DA) . . . ..........................................80

6.11.22 Dial Backup (*DB) . . . . . . . . . . . . . . . . . . . . . ......................80

6.11.23 V.32 Fast Train (*FT) .........................................80

6.11.24 Return to Leased Line from Dial Backup (*LB) ....................81

6.11.25 Line Current Disconnect (*LC) .................................81

6.11.26 Manual Dial Backup (*LD). . . . . . ...............................81

6.11.27 Disable AT Command Set (*NT) ................................81

6.11.28 Answer/Originate (*OR) . . . . . . .................................82

6.11.29 Leased-Line Transmit Level (*TLn)..............................82

6.12 Configuration Commands . . . .......................................82

6.12.1 Modem Power-On Configuration (&W) ...........................82

6.12.2 Reset to Stored Configuration (Z) ................................83

6.12.3 Load Factory Options (&F) . . . . . . ...............................84

6.12.4 View Configuration Profiles/Received Signal Parameters (&V) .........84

6.12.5 Storing a Telephone Command Line (&Z) .........................84

6.12.6 Retaining/Restoring Options (*RO) ..............................85

6.13 Remote Configuration . . . ..........................................85

6.13.1 Security Code (%P=) . . . .......................................85

6.13.2 Remote Configuration (%T=) ...................................86

6.14 Protocol Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86

6.14.1 Operating Mode (\N) . . . .......................................86

6.14.2 Serial Port (DTE) bps Adjust (\J) .................................87

6.14.3 Data Link Flow Control (\G) . . . . . . ..............................87

6.14.4 Serial-Port Flow Control (\Q). . . . . . ..............................88

6.14.5 XON/XOFF Passthrough (\X) ...................................88

6.14.6 MNP Data Compression (%C) ...................................89

6.14.7 Auto-Reliable Fallback Character (%An) ...........................89

6.14.8 Break Control (\Kn). . . . . . . . . . . . . . . . . . . . . ......................90

6.14.9 Maximum MNP Block Size (\A) ..................................92

6.14.10 MNP Inactivity Timer (\T) . . . . . . ...............................92

6.14.11 Protocol Result Codes (\V) . . . . . . ...............................93

6.14.12 Transmit Break/Set Break Length (\B)............................93

6.14.13 Set Auto-Reliable Buffer (\C) ...................................93

6.14.14 Originate MNP Link (\O) . . ....................................94

6.14.15 Accept an MNP Link (\U) . . ....................................94

6.14.16 Switch from Normal to MNP (\Y)................................94

6.14.17 Switch from MNP to Normal (\Z) ................................95

CONTENTS

7. Status Registers . .......................................................96

7.1 How S-Registers Work . . . . ..........................................96

7.2 S-Register Operation . . . . ...........................................97

7.2.1 Individual Bit Command (Sn .(bit#)=v)............................97

7.2.2 Autoanswer (S0=0-255). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

7.2.3 Ring Count (S1=0-255) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

7.2.4 Escape Character (S2=0-255) . . . . . . ..............................98

7.2.5 End-of-Line Character (S3=0-127) ................................98

7.2.6 Line-Feed Character (S4=0-127)..................................98

7.2.7 Backspace Character (S5=0-127) .................................98

7.2.8 Pause Before Dialing (S6=0-255) .................................98

7.2.9 Pause for Ringback Detection/Pause for Carrier Detection (S7=1-30) ....98

7.2.10 Pause Interval for Comma (S8=0-255) ............................99

7.2.11 Carrier Detect Time (S9=0-255) .................................99

7.2.12 Lost Carrier Detect Time (S10=0-255) ............................99

7.2.13 DTMF Tone Duration (S11) . . . . . . ...............................99

7.2.14 Escape Sequence Pause Interval (S12=0-255).......................99

7.2.15 S13. . . . . . . . . ................................................99

7.2.16 S14 (Bit-Mapped Options) . . . . . . ................................100

7.2.17 S15. . . . . . . . . ................................................100

7.2.18 System Tests (S16).............................................101

7.2.19 S17. . . . . . . . . ................................................101

7.2.20 Test Timeout (S18) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .........102

7.2.21 S19, 20. . . . . .................................................102

7.2.22 S21 (Bit-Mapped Options) . . . . . . ................................102

7.2.23 S22 (Bit-Mapped Options) . . . . . . ................................103

7.2.24 S23 (Bit-Mapped Options) . . . . . . ................................103

7.2.25 S24. . . . . . . . . ................................................104

7.2.26 DTR State Recognition Time (S25) ...............................104

7.2.27 RTS/CTS Delay (S26) ..........................................104

7.2.28 S27 (Bit-Mapped Options) . . . . . . ................................104

7.2.29 Loopback Timer (S28) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

7.2.30 S29 (Bit-Mapped Options) . . . . . . ................................105

7.2.31 S30 (Bit-Mapped Options) . . . . . . ................................106

7.2.32 S31. . . . . . . . . ................................................106

7.2.33 S32 (Bit-Mapped Options) . . . . . . ................................107

7.2.34 S33. . . . . . . . . ................................................107

7.2.35 S34 (Bit-Mapped Options) . . . . . . ................................108

7.2.36 S35-38 . . . . . .................................................108

7.2.37 S39 (Bit-Mapped Options) . . . . . . ................................108

7.2.38 S40-51 . . . . . .................................................108

7.2.39 S52 (Bit-Mapped Options) . . . . . . ................................109

7.2.40 801 V.32 Timeout (S53) . . . . . . ..................................109

7.2.41 Flow Control (S54) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .........110

7.2.42 S55, 56. . . . . .................................................110

7.2.43 Number Code Application (S57) .................................110

7.2.44 MNP Inactivity Timer (S58) . . . . . . ...............................111

7.2.42 MNP Break Control (S59) . . . . . . ................................111

7.2.46 S60 (Bit-Mapped Options) . . . . . . ................................112

7.2.47 DTE Speed (S61). . . . ..........................................113

7.2.48 Disconnect Buffer Delay (S62) ...................................113

7.2.49 Maximum MNP Block Size (S63) .................................114

7.2.50 Auto-Reliable Fallback Character (S64) ............................114

MODEM 325 AND MODEM 325 CARD

7.2.51 S65-66. . ....................................................114

7.2.52 Link Speed Status (S67). . . . ....................................114

7.2.53 S68 . . . . ....................................................114

7.2.54 DCE-Independent Speed (S69)..................................115

7.2.55 Operating Mode (S70) .........................................115

7.2.56 Operating Mode Status (S71) ...................................116

7.2.57 S72 (Bit-Mapped Options). . ....................................116

7.2.58 S73-77. . ....................................................116

7.2.59 Autocallback Timer (S78). . . . . . .................................117

7.2.60 Break Length (S79) . . . . . . . . . . . . . . . . . . . . . ......................117

7.2.61 S80-83. . ....................................................117

7.2.62 S84 (Bit-Mapped Options). . ....................................118

8. V.25 bis Autodialer . . . . . . . ..............................................119

8.1 General . . . . . . ....................................................119

Autodialer Command Strings and Parameters ............................119

8.2 Guidelines . . . . ....................................................119

Explanations of Invalid Responses . . . . . . ...............................120

8.3 Dial Parameters . . . . . . .............................................121

8.4 V.25 bis Command and Response Definitions ............................122

8.4.1 Dial Command (CRN

nn...n) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

122

8.4.2 Program Number Command (PRN

a;nn...n) . . . . . . . . . . . . . . . . . . . . . . . .

123

8.4.3 Intermediate Call Progress Responses .............................123

8.4.4 Dial Stored Number (CRS

a) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

123

8.4.5 Request List of Stored Numbers (RLN) ............................123

8.4.6 Disregard Incoming Call (DIC)...................................124

8.4.7 Connect Incoming Call (CIC) . . . . . . ..............................124

8.4.8 Redial Last Number (CRR

n). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

124

8.4.9 Link Number by Address (PRL

a;b). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

125

8.4.10 Request List of Linked Numbers (RLL) ............................126

8.4.11 Request List of Version (RLV). . . . . . ..............................126

8.5 Modem Options Command (PRO

xxx;yy;

0;0) ............................127

8.5.1 Save Current Settings (PRK) . . . . . . ...............................128

8.5.2 Restore Factory Settings (PRP

n) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

128

8.5.3 Request List of Stored Options (RLO

xxx;yy). . . . . . . . . . . . . . . . . . . . . . . . .

129

8.6 Options . . . . . . ....................................................130

Rate Select . . . . ....................................................134

9. Protocols . . . . . . . . . . . . . ................................................135

9.1 MNP/Reliable Mode . . . . ............................................135

9.2 Auto-Reliable. . ....................................................135

9.3 Constant-Speed Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .........135

9.4 Data Compression . . . . . . . ..........................................135

9.5 Normal Mode . . . . . . . ..............................................135

9.6 Direct Mode . . ....................................................135

9.7 Flow Control . . ....................................................135

10. Maintenance . . . . . . . . . . . . .............................................136

10.1 Replacing the Fuse . . . . ............................................136

10.2 Cleaning . . . . ....................................................136

10.3 Preparing for Tests . . . . ............................................136

Appendix A: Phone Jack Descriptions . . . . ....................................137

A.1 Dial-Line Pin Functions . . . ..........................................137

A.2 Telset/Leased-Line Pin Functions . . . . . . ...............................137

CONTENTS

Appendix B: Troubleshooting . . . . ..........................................138

B.1 Telephone Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . .....................138

B.2 Standard Phone . ..................................................138

B.3 Exclusion-Key Telephone . ..........................................138

B.4 Fallback Rates. . . . . . . . . . . ..........................................138

B.5 Modem and Telephone Line Check ...................................139

Appendix C: Command Index and Defaults ...................................142

C.1 General. . . .......................................................142

C.2 Status Registers . ..................................................149

C.3 V.25 bis Dialer Commands. ..........................................151

C.4 Factory Option Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . .....................153

Appendix D: Abbreviations and Acronyms . . . . . . ..............................158

Appendix E: ASCII and EBCDIC Character Table..............................166

MODEM 325 AND MODEM 325 CARD

1. Specifications

Modem Data Rates

—9600 trellis coded, 9600 and 4800 uncoded as stated in CCITT recommendation V.32, 2400 and 1200 compatible with CCITT recommendation V.22 bis, 300 as stated in Bell specification 103

Modulation

—9600, 4800, 2400 QAM with suppressed carrier (V.32, V.22 bis compliant), 1200 PSK,

300 FSK

Transmit Carrier Frequencies

—V.32 bis 1800 Hz

Originate Answer 1200 and 2400 1200 Hz ± 0.01% 2400 Hx ± 0.01% 300 bps Mark: 1270 Hz ± 0.5% 2225 Hz ± 0.5% Space: 1070 Hz ± 0.5% 2025 Hz ± 0.5%

Internal Transmit Clock Frequency

—Selected bit rate ±0.01%

External Transmit Clock Frequency

—Selected bit rate ±0.01%

Transmit Output Level

—0 to -15 dBm, selectable; PSTN operation is programmable or permissive

Operation

—4-wire, full-duplex, leased (private) line; 2-wire, full-duplex, leased (private) line or PSTN

Carrier Detect Level

—Dynamic to -43 dBm

Telco Connection

—Two 8-pin modular jacks, dial and private lines

Testing

—511 PN pattern (per V.52), V.54 remote loopback control

Telephone Line

—Balanced 600-ohm type 3002 or equivalent, 16 dB nominal loss, frequency translation

up to ±10 Hz

Digital Interface

—Conforms to EIA-232D and CCITT V.24

Line Equalization

—Automatic adaptive

RTS/CTS Delay

—From 0 ±2 ms to 90 ±2 ms, user-selectable in 10-ms increments (the default is 0 ms)

Temperature—Operating:

32 to 122 °F (0 to 50 °C);

Storage:

-40 to 158 °F (-40 to 70 °C)

Humidity

—0 to 95% relative humidity, noncondensing

Power

—115 VAC ±10%, 60 Hz, 230 VAC ±10%, 50 Hz, or 12 to 60 VDC

Power Consumption

—9 watts

Fuse

—1/4 Amp slow-blow (115-VAC model)

Size

—2.25"H x 7"W x 10.5"D (5.72 x 17.78 x 26.67 cm)

Weight

—2 lb. 13 oz. (1.28 kg)

CHAPTER 2: Introduction

2. Introduction

2.1 General

The Modem 325 and Modem 325 Card are versatile, secure, and reliable modems that can operate full duplex on both dial-up and leased lines. The modems are compatible with all required standards and recommendations and offer a wide variety of automatic, remote, and backup capabilities. The most notable characteristics are MNP

error-control protocols through Level 5 data compression. Other special features include a V.25 bis autodialer, secure operation, and trellis coding for improved signal-to- noise performance.

The modem operates at data rates of

• 9600 bits per second trellis-coded, as stated in CCITT recommendation V.32

• 9600 and 4800 bps uncoded, as stated in CCITT recommendation V.32

• 2400 and 1200 bps compatible with CCITT recommendation V.22 bis

• 300 bps as stated in Bell specification 103*

Note: 4-wire leased-line mode supports 4800 and 9600 bps only.

2.2 Description

2.2.1 FUNCTIONAL

The Modem 325 processes asynchronous serial data at 19200, 9600, 4800, 2400, 1200, or 300 bps, or synchronous data at 9600, 4800, 2400, or 1200 bps, for transmission over the dial-up telephone network and 2- or 4-wire dedicated leased lines. In 9600-bps trellis mode, near- and far-end echo canceling combine with 8-state, 2-dimensional trellis coded modulation to maximize modem performance, even on lines of reduced quality.

Integral test features allow the operator to determine system performance and isolate faults in the

communications link.

You can configure the modem from the front panel, or with AT or V.25 commands. Changes between

different modes of operation can be made easily and rapidly.

A security scheme prevents unauthorized access by a remote modem.

The V.25 bis autodialer broadens compatibility with host equipment.

2.2.2 P

HYSICAL

The modem is a standalone desktop unit. Operating options are stored in nonvolatile memory. A menu- driven, 32-character LCD provides the operator with command feedback as well as real-time displays of unit operation. Modem and DTE operation can be monitored by six LEDs and the display status screen on the front panel.

Figure 2-1

shows the LCD front panel.

The rear panel (

Figure 2-2

) has an EIA-232 connector for DTE interface, an 8-pin TELSET/LEASED LINE connector, an 8-pin DIAL connector, and the power switch. The fuse and power cord are also on the rear panel.

Inside the modem are two printed circuit boards and the AC line transformer. Hardware straps on the

main board offer additional options.

Note: If you ordered the MD278A-R2, you should have received cables with it.

MODEM 325 AND MODEM 325 CARD

Figure 2-1. Front Panel.

Figure 2-2. Rear Panel.

YES

TALKDATA

Modem 325

TELSET/

LEASED LINE

DIAL

DTE

FUSE

1/4 AMP

115 VAC

1/4 AMP 60 HZ

OFF

CHAPTER 2: Introduction

2.3 How to Use This Manual

2.3.1 SPECIFICATIONS

Modem specifications are listed in

Chapter 1

2.3.2 O

PTION SELECTION

Four methods of selecting or changing modem options are available. You need to read only the part of the manual that deals with the method you’ve chosen.

• LCD—Using the front-panel LCD and pushbuttons for changing modem options is simple and straightforward, and requires the least amount of technical background. See

Chapter 4

• Software program—A wide variety of communication software programs is available, or advanced computer users can write their own software programs that will interact with the modem memory to select options. If you’re using software to configure your modem, follow the software’s instructions.

• AT Commands—The AT compatible command set can be used to select modem options. See

Chapters 6

and7.

• V.25 bis Commands—A set of V.25 bis commands allows selection of modem options during synchronous operation. See

Chapter 8

NOTE

You can select options from the LCD without the DTE or phone line connected.

2.3.3 Q

UICK STARTUP

A quick startup procedure at the beginning of

Chapter 5

provides information for quickly getting online.

MODEM 325 AND MODEM 325 CARD

3. Installation

3.1 General

This chapter provides information for the mechanical and electrical installation of the modem.

3.2 Site Selection

Install the modem within 6 feet of a 115- or 230-VAC grounded outlet as required for the specific model and no farther than 50 feet from the terminal equipment.

The installation area should be clean and free from extremes of temperature, humidity, appreciable

shock, and vibration. Refer to

Chapter 1

for details. Allow clearance for operation and maintenance

access and at least 4 inches at the rear for cables and air flow.

3.2.1 T

OOLS REQUIRED

Normal installation requires a screwdriver to secure the DTE cable to the modem and to attach the telco cable to the phone jack for leased-line operation.

3.2.2 RECEIPT INSPECTION

After unpacking the equipment, check the contents against the packing list. Inspect the equipment for any damage that may have occurred in shipment. If you note any damage or are missing equipment, call your supplier. Keep the shipping container and material for future shipment.

3.3 Electrical Installation

The rear panel (

Figure 3-1

) houses the power cord and connectors for the DTE and telephone lines.

Figure 3-1. Rear Panel I/O.

AUX

LINE

DTE

3/16

FUSE

AMP S.B. POWER

115 VAC

60 HZ 14W

OFF

CHAPTER 3: Installation

AC POWER CONNECTION

Power is supplied through a 6-foot line cord with a grounded 3-wire plug. If chassis ground is available through the third prong of the plug, a separate ground wire is not required.

CAUTION

To protect the DC-to-DC converter from reverse-polarity damage, make sure that the positive and negative leads are properly connected.

The modem can be ordered for DC power input. Connect 12 to 60 VDC power to the terminal block

attached to the modem back panel. A chassis ground connection is also supplied on the terminal block.

3.4 DTE Connection

The DTE connector is a 25-pin D-series type conforming to EIA-232 specifications. The digital interface signals are illustrated in

Figure 3-2

and described in

Table 3-1

MODEM 325 AND MODEM 325 CARD

Figure 3-2. Digital Interface Signals.

MODEM MODEM

TRANSMIT DATA (BA)

EXT TX CLOCK (DA)

TX CLOCK (DB)

REQUEST TO SEND (CB)

CLEAR TO SEND (CB)

DATA SET READY (CC)

DATA TERMINAL READY (CD)

RECEIVE DATA (BB)

RECEIVE CLOCK (DD)

CARRIER DETECT (CF)

RING INDICATOR (CE)

TRANSMITTER RECEIVER

TRANSMISSION

FACILITY

DIRECT

CONNECT

CIRCUITRY

RECEIVER TRANSMITTER

DIRECT

CONNECT

CIRCUITRY

DATA TERMINAL READY (CD)

RECEIVE DATA (BB)

RECEIVE CLOCK (DD)

CARRIER DETECT (CF)

RING INDICATOR (CE)

DTEDTE

TRANSMIT DATA (BA)

EXT TX CLOCK (DA)

TX CLOCK (DB)

REQUEST TO SEND (CA)

CLEAR TO SEND (CB)

DATA SET READY (CC)

CHAPTER 3: Installation

Table 3-1. Digital Interface Signal Descriptions.

Pin EIA-232D CCITT Signal Name Description No. V.24

1 101 Shield No connection

2 BA 103 Transmitted Data Serial digital data (to be modulated) from a

data terminal or other digital data source: Synchronous data must be accompanied by the modem transmit clock (pin 15) or by an external data rate clock (pin 24). Data transitions should occur on positive-going clock transitions; asynchronous data does not require a transmit clock.

3 BB 104 Received Data Serial digital data output to the DTE

interface: Sync data is accompanied by an internal data rate (receive) clock (pin 17) that has positive-going transitions on the data transition. Async data does not require a receive clock.

4 CA 105 Request to Send A positive level to the modem when data

transmission is desired.

5 CB 106 Clear to Send A positive level from the modem in response

to request to send and when the modem is ready to transmit.*

6 CC 107 Data Set Ready A positive level from the modem when

power is on and ready to operate: In dialup operation, the modem must be off hook to give a high DSR signal.*

7 AB 102 Signal Ground or Common signal and DC power ground.

Common Return

8 CF 109 Received Line A positive level from the modem

Signal Detector indicating the presence of a received signal

(carrier detect).*

9 +12 Volts +12 voltage reference

10 -12 Volts -12 voltage reference

*Modem options may force these signals on or cause them to be ignored.

MODEM 325 AND MODEM 325 CARD

Table 3-1 (continued). Digital Interface Signal Descriptions.

Pin EIA-232D CCITT Signal Name Description No. V.24

11 Signal Quality Indicator This circuit indicates probability of errors in

the received data. A positive level indicates poor signal quality; a negative level indicates good signal quality.‡

15 DB 114 Transmit Clock (DCE) A transmit-data-rate clock output for use by

an external data source: Positive clock transitions correspond to data transitions.

17 DD 115 Receive Clock A receive-data-rate clock output for use by

an external data sink: Positive clock transitions correspond to data transitions.

18 141 Local Loopback A positive level causes the modem to enter

(Loop 3) Control the local analog loopback test mode.

20 CD 108.2 Data Terminal Ready This circuit is positive when the DTE is ready

to originate or answer a call in dialup operation. DTE must always be active (high) in 2-wire private line operation. Cycling DTR causes retraining.*

21 140 Remote Digital A positive level causes a digital loopback test

Loopback mode at the remote modem.

22 CE 125 Ring Indicator In direct-dial operation, this circuit is positive

in response to an incoming ring signal.

23 CH 111 Data Rate Select Supplies a data rate control input to select

primary or fallback data rate: Negative voltage selects primary data rate and positive voltage selects fallback data rate.

24 DA 113 External Transmit A serial data rate clock input from the data

Clock source. Positive clock transitions correspond

to data transitions.

25 142 Test Mode Indicates the modem is in a test mode.

*Modem options may force these signals on or cause them to be ignored. ‡This function can be disabled or its logic sense reversed by hardware straps. Refer to Strap Options.

CHAPTER 3: Installation

3.5 Telephone Cables

The cables used for connection between the modem and the various telco jacks are shown in

Figure 3-3

The part number is printed on the cable.

Part Number Modem Connection Mechanical Layout Telco Connection Telco Jack

Figure 3-3. Telephone Cables.

8-PIN

Included

EL08MS-0006

Included

EL08MS-0006

6-PIN

RJ-11

Permissive

Pins 4 and 5

connected

Pins 3 and 4

connected

6 Feet

2-Wire Cable

6 Feet

8-PIN

Pins 3-8

connected

Pins 3-8

connected

RJ-48S

Programmed

RJ41S

(Prog Only)

Leased Line

Cable

For use with

42A Block

4-Spade

Lug

8-Pin

Pins 1, 2, 7, 8

connected

Pins 1, 2, 7, 8

connected

Pins 1, 2, 7, 8

connected

6-Wire Cable

4-Wire Cable

8-Pin

Leased Line

Cable for use

with JM8 Jack

MODEM 325 AND MODEM 325 CARD

3.6 Telephone Line Connection

The modem operates in one of three modes:

• Permissive (PSTN)

• Programmable (PSTN)

• Private line

Permissive and programmable modes are used on the dial-up Public Switched Telephone Network (PSTN). Private-line mode is used on 4-wire or 2-wire dedicated leased lines. The user must decide which mode to use and then select the telephone jacks accordingly.

3.6.1 PSTN C

ONNECTION

This modem is registered by the Federal Communications Commission (FCC) for direct connection to the PSTN. The label on the chassis bottom gives the FCC registration number and other information.

Direct connection to the PSTN provides two modes of operation (

Figure 3-4

• Permissive

• Programmable

3.6.2 P

ERMISSIVE

In permissive mode, the modem transmits a maximum signal level of -9 dBm. Signal loss between the modem and telephone company central office is not controlled. Jack arrangements for this mode are the RJ-11C for standard telephones and the RJ-16X for exclusion key telephones. This cable (included) is used to connect the DIAL jack on the back of the modem to the RJ-11C or RJ-16X wall jack.

3.6.3 P

ROGRAMMABLE

Programmable mode corrects for the signal-level loss between the modem and the telephone company’s central office. This is done by setting the modem’s transmit-output signal level with a fixed-value programming resistor selected and installed in the jack by the telephone company. This allows the output signal to reach the central office at the optimum level of -12 dBm. Jack arrangements for this RJ-45S and RJ-41S jacks are used for this mode. RJ-41S has a switch option that must be selected to Programmed (P). Cable EL08MS-0006 is used to connect the DIAL jack on the back of the modem to the RJ-41S or RJ-45S wall jack.

CHAPTER 3: Installation

Figure 3-4. Permissive or Programmable Connection.

Telset/Leased Line

8-pin connector

Dial 8-Pin

Connector

DTE Connector

Screws

Cable

Supplied

with

Telephone

RJ-11C, RJ-45S,

or RJ-41S jack

installed by

telephone

company

Use the included cable

with the RJ-11 jack, or

EL08MS-0006.

DTE cable

EIA-232 25-Pin

Connector to

DTE

TELSET/

LEASED LINE

DIAL

DTE

FUSE

MODEM 325 AND MODEM 325 CARD

NOTE

The modem is compatible with exclusion key phone arrangements.

3.6.4 LEASED-LINE CONNECTION

Leased lines use either a 2-wire or 4-wire connection. The telephone company will install the leased line and wall jack at your site. The line connects to the modem at the 8-position TELSET/LEASED LINE jack.

The 42A block is most common for leased-line use. It requires the use of the 8-pin-modular-to-spade- lug cable (included).

Figure 3-5

illustrates the typical hook-up of the modem for operation over private

leased lines with dial backup.

NOTE

Some Bell operating companies have discontinued the 42A block for leased-line terminations. Instead, the modular jack JM8 is used. If this is the case in your area, you need a special cable (EL08MS-0006). Contact technical support for further information.

CHAPTER 3: Installation

Figure 3-5. Leased-Line Connection.

Telset/

Leased Line

Dial Line (may be

used for dial

backup)

Included cable (must

use for leased-line

connection)

EIA-232 25-pin

connector to DTE

RJ-11C,

RJ-45S, or

RJ-41S

Use the included cable with the RJ-11

jack, or EL08MS-0006.

42A

block

TELSET/

LEASED LINE

DIAL

DTE

FUSE

Central

Office

42A block

Red

Green

Black

Yellow

Screw Terminal

Spade

lug

Ring (R)

Tip (T)

Tip (T1)

Ring (R1)

Pin#

TX pair

4-wire or

TX and RX

2-wire

RX pair

4-wire

modem

MODEM 325 AND MODEM 325 CARD

4. Option Selection

4.1 General

NOTE

This chapter contains the options available by pushbutton in response to the LCD.

There are four factory option sets to choose from. The modem is shipped configured to factory option set #1 (see Appendix D). Because of the number of possible applications, most modems require some option changes to fit into the network.

A user programmed option set is available for storing a custom configuration.

4.2 Strap Option Selection

Modem configuration is determined by front panel controls, AT commands,and hardware option straps located on the pc board. Remove the modem cover for access to the option straps.

NOTE

Normally, PC board straps will not have to be changed.

REMOVING

COVER

WARNING

Disconnect AC power before removing the cover. Although dangerous voltage levels are not exposed, disconnecting power eliminates the hazard of electrical shock.

Place the unit on its side on a flat surface. Insert a medium-size flat screwdriver blade in one of the bottom rear latch slots. DO NOT PUSH the screwdriver but lightly pry the handle away from the unit as illustrated in

Figure 4-1

. This will disengage the lock prong from the lock clip. Assist removal by pushing the cover from the chassis with your fingers on the rear edges of the unit. Repeat this procedure with the remaining three latch slots.

To replace the cover, align the lock clips, rear guide grooves, and front lock tabs. Press the cover in

place until the lock clips engage the lock prongs.

Figure 4-2

shows typical strap configurations and

Figure 4-3

shows strap locations.

CHAPTER 4: Option Selection

Figure 4-1. Removing the Cover.

Figure 4-2. Option Strap Configuration.

Chassis Bottom

Lock Prong

Lock Clip

Cover

MODEM 325 AND MODEM 325 CARD

Figure 4-3. Strap Locations.

Speaker

Factory use only Do not change

NORM

Tip and Ring NORM/REV

REV

Ground Option

SIG GND CH GND

QM Disable Option

DIS

CHAPTER 4: Option Selection

4.3 Hardware Straps

4.3.1 TIP AND

RING POLARITY

Some telephones are sensitive to tip and ring polarity. If a dial tone is detected after dialing, reverse these two straps.

Figure 4-4. Tip and Ring Polarity Jumper.

4.3.2 G

ROUND OPTION STRAP

Signal ground is normally connected to chassis ground. If interference exists, isolate signal ground from chassis ground.

Figure 4-5. Ground Option Strap.

Normal tip and

ring connection

Reverse tip

and ring

connection

Signal ground connected to

chassis ground selected

NORM

REV

NORM

REV

CH GNDSIG GND

MODEM 325 AND MODEM 325 CARD

4.3.3 QM DISABLE OPTION

When enabled, the Quality Monitor (QM) output is connected to the EIA-232 (pin 11) interface. Disabled disconnects the QM output. Refer to

Chapter 5

and

Table 3-1

for more QM information.

Figure 4-6. QM Disable Option Jumper.

4.4 LCD Option Selection

The modem options can be observed or changed through the front-panel LCD. The LCD also gives modem status.

4.5 Main Menu

There are six main menus that support modem operations:

• MODEM STATE

• DIAL STORED NUMBER

• DISPLAY STATUS

• SELECT TEST

• MODIFY CONFIGURATION

• CHANGE PHONE NUMBERS

Each main menu is supported by various submenus, items, and options (

Table 4-1

). The two right

columns in the table show the associated AT commands and S-registers as a cross reference.

ENU SEQUENCE

Main menus consist of six displays which allow access to submenus. Each submenu has a submenu item column; if an option setting is selected or if all options have been scrolled through, the menu will return to the submenu header.

If the NO pushbutton is pressed and held, the modem automatically scrolls through the menu.

QM output not connected to

EIA-232 interface

DISEN

CHAPTER 4: Option Selection

NOTE

Main Menu 1 does not scroll. The displays in Main Menu 1 show the current operating mode or status. These displays are the results of other selected options and are not themselves option selections.

While operating in the option menu, pressing NO scrolls vertically down the columns in Table 4-1 and pressing YES advances horizontally across the columns.

Table 4-1. Menu Options.

Main Menu LCD Messages

M V.32 9600 IDLE (Press NO to advance to MAIN 2) A V.32 9600 TALK I V.32 9600 TRAINING N V.32 9600 ONLINE 1 V.32 9600 RINGING

V.32 9600 IN TEST

MAIN MENU SUBMENU SUBMENU ITEM AT S-REG

ITEM OPTION COM.

M DIAL STORED DIAL #1-9 YES, NO DSn (n=1-9) — A NUMBER ? I N 2

M DISPLAY DTE SIGNALS DTR ON/OFF DISPLAYS — — A STATUS ? DSR ON/OFF STATUS I (status only) OH ON/OFF N RI ON/OFF 3

MNP LEVEL NEGOTIATING DISPLAYS — —

MNP LEVEL STATUS MNP LEVEL 2, 3, 4, OR 5 CONNECTION

MODEM 325 AND MODEM 325 CARD

Table 4-1 (continued). Menu Options.

MAIN MENU SUBMENU SUBMENU ITEM AT S-REG

ITEM OPTION COM.

CARRIER RECEIVE LEVEL DISPLAYS — — DESCRIPTIONS NEAR END ECHO STATUS

LEVEL FAR END ECHO LEVEL ESTIMATED DELAY FREQUENCY TRANSLATION

M SELECT LOCAL ANALOG INITIATE, &T1 S16 A TEST ? LOOP EXIT I N LAL WITH TP INITIATE, &T8 S16 4 EXIT

(4-wire only) REMOTE INITIATE, &T2 S16

ANALOG LOOP EXIT

RAL WITH TP INITIATE, &T9 S16

EXIT

LOCAL DIGITAL INITIATE, &T3 S16 LOOP EXIT

REMOTE DIGITAL INITIATE, &T6 S16 LOOP EXIT

RDL WITH TP INITIATE, &T7 S16

EXIT

TEST PATTERN INITIATE, %T —

M MODIFY CHANGE MODEM CHANGE DCE DTE SPEED %B S69 A CONFIGUR- OPTIONS? RATE 9600 TRELLIS %B6 I ATION 9600 UNCODED %B5 N 4800 UNCODED %B4 5 2400 V.22 bis %B3

1200 V.22 bis %B2 300 BELL 103 %B1

CHAPTER 4: Option Selection

Table 4-1 (continued). Menu Options.

MAIN MENU SUBMENU SUBMENU ITEM AT S-REG

ITEM OPTION COM.

M MODIFY CHANGE MODEM FORCED ANSWER NORM ORIGIN *OR S14 A CONFIGUR- OPTIONS? OR NORMAL FORCED *OR1 I ATION (CONT) ORIGINATE ANSWER N 5 V.32 FAST TRAIN ENABLE, DIS *FT1, *FT S29

AUTO RETRAIN ENABLE, DIS %E1, %E S60

TRANSMIT CLOCK INTERNAL &X S27

EXTERNAL &X1 RECEIVE &X2

LINE TYPE LEASED, DIAL &L1, &L2, S27

JACK TYPE PER—RJ-11 %Z —

PROG—RJ-15 %Z1

LINE CURRENT OFF, 8 MS *LC, *LC1 S32 DISCONNECT 90 MS *LC2

LONG SPACE ENABLE Y1 S21 DISCONNECT DISABLE Y

V.32 CLEARDOWN ENABLE H2 S14

DISABLE H3

V.22 GUARD TONEDIS, 550 &G, &G1 S23

1800 Hz G2

(Leased Only) 2-WIRE/4-WIRE 2-WIRE/4-WIRE &L1, &L2 S32

DIAL BACKUP MANUAL, AUTO *DB, *DB1 S32

LOOPBACK TIMER OFF, 15, 30, 45 — S28

60 MIN

TRANSMIT LEVEL 0 TO -15 dB *TLn S52

MODEM 325 AND MODEM 325 CARD

Table 4-1 (continued). Menu Options.

MAIN MENU SUBMENU SUBMENU ITEM AT S-REG

ITEM OPTION COM.

CHANGE MNP MNP PROTOCOL ENABLE \N2, \N3 S70 OPTIONS? DISABLE \N, \N1 (Async Only)

AUTO FALLBACK/ DISCONNECT \N2 S70 DISCONNECT FALLBACK TO \N3 (If MNP Proto En) NON EC MODE

DTE SPEED DTE=DCE \J1 S72

CONSTANT DTE \J

MNP FLOW DISABLE \Q S54 CONTROL XON/XOFF \Q1

CTS only \Q2 RTS/CTS \Q3

XON/XOFF PASS ENABLE \X1 — THROUGH DISABLE \X

DATA ENABLE %C1 S60 COMPRESSION DISABLE %C

MNP INACTIVITY OFF, 15, 30, 45 — S58 TIMER 60, 75, 90 MIN

MNP BREAK 0, 1, 2, 3, 4, 5 \K, \K1, S59 CONTROL \K2, \K3,

\K4, \K5

M CHANGE DTE OPERATION SYNC &M1, S27 A OPTIONS? &M2, I &M3, N &M4, 5 &M5

ASYNC &M S30

DTE RATE 19200, 9600, — S61 (Async) 4800, 2400,

1200, 300

CHAR SIZE 7 BIT — S61 (Async) 8 BIT

CHAPTER 4: Option Selection

Table 4-1 (continued). Menu Options.

MAIN MENU SUBMENU SUBMENU ITEM AT S-REG

ITEM OPTION COM.

PARITY (Async) NO, EVEN, ODD — S61

AT COMMAND ENABLE *NT1 S29 SET DISABLE *NT

DIAL METHOD ASYNC DTR, &M1, &M2 S27 (Sync) MANUAL, &M3 (Async allows V.25 BISYNC, &M4 S30 DTR control) V.25 SDLC &M5

CHARACTER ASCII, EBCDIC — — TYPE (V.25 only)

DTR RESPONSE IGNORE &D S21

RECALL CMD D1 DISCONNECT D2 RESET D3

DSR STATE NORMAL &S1 S21

FORCED HIGH &S OFF 5 SEC ON &S2 DISCONNECT FOLLOWS OH &S3

DCD STATE NORMAL &C1 S21

FORCED HIGH &C OFF 5 SEC ON DISCONNECT &C2 FOLLOWS REMOTE RTS &C3

CTS STATE NORMAL &R S21

FORCED HIGH &R1 CTS FOLLOWS &R2 S72 DCD CTS=RTS &R9 S72

MODEM 325 AND MODEM 325 CARD

Table 4-1 (continued). Menu Options.

MAIN MENU SUBMENU SUBMENU ITEM AT S-REG

ITEM OPTION COM.

RTS/CTS DELAY 0 to 90 ms — S26

(10 ms)

DTE COMMANDED ENABLE *FB1 S53 FALLBACK DISABLE *FB

OPTIONS RES/ RESTORED *RO1 S29 RETND AT DISC RETAINED *RO

CHANGE TEST BILATERAL ENABLE *AN1 S34 OPTIONS? ANALOG LOOP DISABLE *AN

BILATERAL ENABLE *DG1 S34 DIGITAL LOOP DISABLE DG

DTE LOCAL ENABLE *LA1 S34 TEST DISABLE *LA

DTE REMOTE ENABLE *RD1, S34 TEST DISABLE *RD

REMOTE ENABLE &T4 S23 COMMANDED DISABLE &T5

TEST TIMEOUT OFF, 60, 120, — S18

180, 240 SEC

CHANGE DIAL DIAL TYPE PULSE, TONE P, T S14 OPTIONS?

AUTODIAL # OFF, 1-9 *AUn —

(n=1-9)

DIAL TONE BLIND DIAL X, X1, X3 S22

WAIT FOR DIAL X2, X4 TONE

WAIT DELAY 1, 2, 3, 4, 8, 16 — S6 (Blind Dial) 32 SEC

PAUSE DELAY 1, 2, 3, 4, 8, 16 — S8

32 SEC

CHAPTER 4: Option Selection

Table 4-1 (continued). Menu Options.

MAIN MENU SUBMENU SUBMENU ITEM AT S-REG

ITEM OPTION COM.

CALL TIMEOUT 15, 30, 45, 60, 75, — —

90, 105, 120 SEC

ANSWER RING #X MANUAL, 1, 2, 4, — S0

8, 16

801 V.32 TIMEOUT LONG, SHORT — S53

AUTOCALLBACK ENABLE, — S72

DISABLE

CHANGE VOLUME LOW L1 S22 SPEAKER CONTROL MEDIUM L2 OPERATION? HIGH L3

SPEAKER ON UNTIL CARR S22 CONTROL DETECT M1

ALWAYS ON M2 OFF WHILE DIALING M3 ALWAYS OFF M

LOAD/STORE LOAD FACTORY NO, 1, 2, 3, 4, &Fn — OPTION SET? OPTION RESET (n=1-9)

SECURITY?

STORE PRESENT YES, NO &W — OPTIONS

M CHANGE PHONE NUMBER NO/ &Zn — A PHONE NINE 31-CHAR (n=phone # I NUMBERS? NUMBERS and dial N modifiers) 6 *CNn,x

MODEM 325 AND MODEM 325 CARD

4.6 Option Selection

Options are selected by pressing the YES/NO buttons. When powered up, the modem will go to the selected display under the Main Menu 1 header in

Table 4-1

. Any time a Main Menu is displayed,

pressing NO scrolls through the Main Menus. When the end is reached, the display returns to main #2.

NOTE

Certain options depend on or are restricted by the mode of operation. For example, dial backup is not available in V.22 mode.

NO DIAL STORED NO DISPLAY NO CHANGE

NUMBER STATUS? PHONE #?

4.6.1 M

AIN MENU

When any Main Menu is on display, pressing YES advances to the first Submenu in that Main Menu group.

MODIFY YES CHANGE MODEM CONFIGURATION? OPTIONS?

4.6.2 S

UBMENU

When in a Submenu column, pressing NO will scroll down the Submenu and when the end is reached will return to the Main Menu header for that Submenu group.

CHANGE MODEM NO LOAD/STORE NO MODIFY OPTIONS? OPTION SET? CONFIGURATION?

When in a Submenu column, pressing YES advances to the Submenu Item column.

CHANGE MODEM YES DCE RATE OPTIONS?

4.6.3 S

UBMENU ITEM

When in a Submenu Item column, pressing NO will scroll through the items and when the end is reached will return to the Submenu header for that item group.

DCE NO ORIG/FORCE NO V.22 GUARD TONE NO CHANGE MODEM RATE ANSWER? DISABLED* OPTIONS?

*This is the last submenu item for modem options.

When in a Submenu Items column, pressing YES advances to the Option Setting for that Submenu

Item. The first option that appears is the currently selected option.

NORMAL ORIG. FORCED YES FORCED ANSWER NORMAL ANSWER? ORIG.?

CHAPTER 4: Option Selection

4.6.4 ITEM OPTION

When in the Item Option column, respond to the prompt question on the LCD to either keep or change the current display.

USE RECEIVE NO USE EXTERNAL NO USE INTERNAL YES INTERNAL TRANSMIT TRANSMIT TRANSMIT CLOCK CLOCK? CLOCK? CLOCK? CHANGE?

4.6.5 SELECTING THE OPTION

Select the submenu containing the option (submenu item) to be changed and press YES. The LCD displays the first submenu item.

If the first submenu item (option) setting displayed is the desired option, press NO to scroll through Submenu Items. If the first setting displayed is not the desired setting, respond to the prompts until the desired setting is displayed, then advance to the next submenu item. In any case, responding to the prompt will guide you to the desired option.

NOTE

Because of menu structure and options available, not all Main Menus have Submenus and not all Submenus have Item Options. However, the option selection sequence is the same.

MODEM 325 AND MODEM 325 CARD

5. Operation

5.1 General

This chapter contains a functional description of the modem.

5.2 Controls and Indicators

The front panel houses the LCD panel and LED indicators. The power switch is located on the rear panel.

5.3 LED Descriptions

The LEDs display modem status during various operations.

5.3.1 R

EQUEST TO SEND

RS—lights when the data terminal is ready to send data to the modem. This signal is input on EIA-232 pin 4.

5.3.2 C

LEAR TO SEND

CS—lights when the modem is ready to accept data from the terminal. This signal is output on EIA-232 pin 5.

5.3.3 QUALITY MONITOR

QM—lights when poor signal quality produces a bit error rate of 1 x 104 or greater. This signal is output on EIA-232 pin 11.

5.3.4 CARRIER DETECT

CD—lights when the received audio carrier signal is detected or, if enabled, when V.42 negotiation is complete. This signal is output on EIA-232 pin 8.

5.3.5 R

ECEIVED DATA

RD—lights for a space at the receive data output, indicating receive output data activity. This signal is output on EIA-232 pin 3.

5.3.6 TRANSMIT DATA

TD—lights for a space at the transmit data input, indicating transmit input data activity. This signal is input on EIA-232 pin 2.

5.4 Getting on Line Quickly

Turn the power switch on the rear panel ON.

This procedure can help with first time operation of the modem. The procedure assumes that phone numbers have been inserted in memory, that an asynchronous dial-up option set is in effect, that power, DTE, and telephone line connections are made, and that a similar, remote station is available for communication.

CHAPTER 5: Operation

• Ensure the modem is installed according to the instructions in

Chapter 3

• Turn on the computer and the modem.

5.4.1 M

ANUAL

IALING

After turning the modem on the LCD shows the software version and advances to main menu 1.

• Press TALK/DATA. The display will show V.32 9600 TALK.

• Pick up the handset and dial the phone number of the remote modem.

• If the remote modem is set for autoanswer, a high-pitched tone (a 2100-Hz answer-back tone) is heard.

• Press TALK/DATA. This puts your modem in the DATA mode and data transfer can begin.

The display shows TRAINING as the modems negotiate a connection and then ONLINE when the

connection is made.

5.4.2 M

ANUAL ANSWERING

The modem will autoanswer in both TALK or IDLE mode. To manually answer the phone for conversation, set the front panel to TALK and the autoanswer register (S0) to a ring count value high enough to allow answering the call before autoanswer does.

When conversation is completed, both parties press TALK/DATA and a data connection is established.

5.4.3 AUTODIAL

(FRONT P

ANEL)

• Starting at the V.32 9600 IDLE display, press NO. The display advances to DIAL STORED NUMBER?

• Respond to the prompts until you reach the desired number to dial.

• Press YES. The modem will go through the dial sequence and establish a connection.

• You can follow this sequence of events by observing the LCD and listening to the speaker.

5.4.4 AT C

OMMAND DIALING

Starting from V.32 IDLE or TALK and using a computer in terminal mode, enter ATD and the telephone number to dial or ATDS and the memory location to dial. When the enter key is pressed the dial sequence starts. You can follow the status of the dial sequence by observing the monitor screen and listening to the speaker.

5.4.5 S

OFTWARE COMMUNICATION PACKAGES

A large variety of software packages compatible with the modem is available. Most of them provide a means for the operator to select options, insert phone numbers, and establish communications with a remote station. See the instructions for your software.

5.5 Error Control

The modem provides error detection and automatic retransmission of data upon detection of an error. The retransmission buffer is 2048 bytes long and can accommodate up to eight frames. MNP levels 2, 3, 4, and 5 are supported. Level 2 is the asynchronous link version, level 3 is the synchronous link version, level 4 is synchronous with optimized headers for increased efficiency, and level 5 implements data compression for increased data throughput. When making a call in dial mode, the modem negotiates the highest protocol common to both modems. If the connection cannot be established, the modem continues through successive protocols until all are tried or a connection is made.

MODEM 325 AND MODEM 325 CARD

5.6 Flow Control

Flow control adjusts for differences in speed between the modem and DTE. The DTE can operate at a constant speed independent of the bit rate of the modem.

Flow control works in both directions. The modem can start and stop the DTE transmitter and the DTE can start and stop the modem transmitter. Both inband and out-of-band flow control are implemented. Inband methods employ the characters DC1/DC3 (11 hex / 13 hex). Out-of-band flow control is accomplished with the CTS and RTS interface leads.

5.7 Autobaud

With autobaud, the modem will automatically detect DTE speed and adjust to communicate with the DTE at that rate as soon as it receives the first “AT.” The protocol processor will default to 9600 bps. Autobaud also detects the character size and parity used by the DTE.

NOTE

Autobaud overrides the LCD selection for DTE speed, character length, and parity.

5.8 4-Wire Operation

When configured for 4-wire operation, the modem is a full-duplex leased-line modem requiring a dedicated 4-wire leased line. Only point-to-point dedicated leased lines are supported. The 4-wire leased line is connected to the TELSET/LEASED LINE jack on the rear panel. Dialing is not necessary. When connected via leased line, the modems will train and begin communicating with each other. The DIAL jack can be used to connect a 2-wire PSTN line for dial backup.

NOTE

One modem must be configured for forced answer and MNP options must be the same on both ends of a 4-wire leased line for the connection to be successful.

NOTE

4-wire leased-line mode supports 4800 and 9600 rates only and incorporates a CCITT V.33like training sequence. The modem will not connect with a 4-wire leased-line modem using a CCITT V.32-type training sequence.

5.9 2-Wire Operation

When configured for 2-wire operation, the modem is a full-duplex modem able to operate over 2-wire leased or PSTN lines.

5.9.1 2-W

IRE L

EASED-LINE OPERATION

The 2-wire leased line is connected to the TELSET/LEASED LINE jack; the DIAL jack is used to connect a 2-wire PSTN line for dial backup. The leased line connects the local and remote modems directly, so dialing is not necessary. One of the modems must be configured for FORCED ANSWER. When connected via leased line, the modems will train and begin communicating with each other.

CHAPTER 5: Operation

NOTE

DTR must be held high in 2-wire leased line operation. This is accomplished by DTE control, wiring pin 20 of the digital interface cable high, or by selecting the option, IGNORES DTR. If DTR is terminal controlled, loss of synchronization can be corrected by cycling DTR. This causes the modem to initiate the 2-wire training sequence. DSR goes off during the training procedure.

5.9.2 2-W

IRE DIAL-UP O

PERATION

Connection to the telephone network is through the DIAL jack. A standard telephone connects to the TELSET/LEASED LINE jack.

5.10 Remote Configuration

You can also configure the modem remotely from another modem.

To start configuring the modem remotely, enter AT%T=. The remote modem is now in remote

configuration mode, and you can configure it just as you would a local modem.

If you need to put your local modem back in DTE mode, use the escape sequence (+++).

To put the remote modem back in DTE mode, use the command ATO. You can switch DTE service

between the local and remote modems as needed.

To exit remote configuration, use the command AT&T.

security code

will prevent unauthorized users from reconfiguring your modem remotely. To set up a security code, use the command AT%P=<code>. The code can be any number from 0 to 99999999. For example, to set up 12345 as the security code, enter AT%P=12345. By default the code is blank, which means there is no security code.

Once you have set up a security code, you will have to enter remote configuration with the command AT%T=<code>. For example, if you have set up 12345 as the security code, then use the command AT%T=12345 to enter remote configuration.

To find the security code of your

local

modem, enter AT%P?.

To disable remote configuration entirely, enter AT%P=D. No one—including you—will be able to configure your modem remotely until you enter a different security code, or eliminate security altogether with the command AT%P=.

You can dial the modem and go directly into remote configuration by placing the AT*T command— without the “=” but followed by the security code (if there is one)—at the end of the dial string.

5.11 Secure Operation

Secure operation provides password protection against unauthorized dial-up access. The security feature can be enabled with AT commands when operating on a dial-up system and requires the secure modem to be set for MNP or buffered mode.

Security may be enabled or disabled. TXD and RXD are suppressed to the host DTE before and during security validation; all other signals (CTS, DSR, RI, etc.) operate as configured. After the password has been validated, the modem operates like a standard V.32 unit. Security has no front-panel operation except for the RESET SECURITY? prompt in the FACTORY OPTIONS submenu. Resetting security clears both passwords and turns security off.

MODEM 325 AND MODEM 325 CARD

5.11.1 OPERATING WITHOUT SECURITY

The modem operates like a standard V.32 modem, except that several additional AT commands are available to access security. With these commands, any user can set the passwords and turn security on when the modem is not already secure.

5.11.2 O

PERATING WITH SECURITY

A secure modem will not allow data transfer between its host and a remote host until a correct password is received from the calling party. If an incorrect password is received, the secure modem disconnects. The front panel is not locked out, since the primary reason for security is to prevent unauthorized dial-up access.

5.11.3 R

EMOTE OPERATION

The remote modem must pass security validation before the secure modem will allow data transfer. Once communication has been established, the secure modem prompts the originator with

PLEASE ENTER YOUR PASSWORD ===>>

To respond to the password prompt, enter $ as a lead-in character followed by the password.

After receiving the $, the modem collects up to ten characters until the user presses the carriage return. Entering more than ten characters causes the secure modem to disconnect. After receiving a valid password the secure modem sends PW ACCEPTED to the originating modem.

5.11.4 L

OCAL OPERATION

When accessing the local modem, the password is not required except when the user wants to change a security option. To change a password or to turn security on or off, the user must enter a password when entering the appropriate AT commands. The EIA-232 signals to the DTE are not affected by security.

5.11.5 P

ASSWORDS

Two passwords of up to ten characters each are stored in the modem’s nonvolatile memory. AT commands change the passwords. Backspace and escape keys are not supported for password entry. The passwords can consist of any printable characters except a dollar sign, a comma, and a space. Passwords are case-sensitive.

The passwords have the same priority level and may be substituted for each other. This can be helpful in some situations, such as when the user forgets one of the passwords.

5.11.6 LCD I

NDICATION OF SECURITY

The front-panel LCD indicates whether security is enabled or not. If security is disabled, screens referring to security do not appear on the LCD. If security is enabled, main #1 consists of the following display:

SECURE 9600

XXXX

CHAPTER 5: Operation

5.11.7 SECURITY RESET

The only security operation available through the front-panel menu is RESET SECURITY. If you forget both passwords, this option will reset security to its initial state (off and with no passwords stored). This option is located under the LOAD FACTORY OPTIONS menu:

RESET SECURITY?

PUSHBUTTON ACTION

YES - Advances to ERASE ALL

SECURITY INFO?

NO, TALK/DATA - Returns to submenu LOAD OR STORE OPTION SET?

5.11.8 S

ECURITY COMMANDS

The following AT commands operate security:

AT$S=x Sets an empty password location to x. This command only applies when no

password or only one is stored in memory. It can not be used to change a password.

AT$C=x, y Changes either password, where x is the old password and y is the new one.

AT$C=x,- This deletes password x from memory. Security is automatically disabled

if the last password is deleted.

AT$E=x Enables security, where x is either password.

AT$E? Displays the current status of security (on or off).

AT$D=x Disables security, where x is either password.

AT$D? Displays the current status of security (on or off). Same as AT$E?.

AT$DR Resets security to its initial state (off with no passwords stored).

x and y indicate passwords

5.11.9 R

ESTRICTIONS IN SECURITY OPERATION

The following conditions will cause the modem to disconnect.

• Caller is 300 bps

• Caller is synchronous

• Secure modem has protocol or buffers disabled

• Caller gives wrong password

These restrictions apply only when security is enabled.

MODEM 325 AND MODEM 325 CARD

5.12 Dial Backup

Dial backup allows the modem to switch to a dial-backup mode if the data connection on the leased line becomes unacceptable for communications. This can be accomplished in two ways:

• Automatic—the modem can be set to switch to the backup line automatically after an extended loss of carrier or 4 unsuccessful retrains in 3 minutes

• Manual—you can switch to dial backup from the front panel or with the *LB or *LD command.

* Not supported in V.22 mode.

CAUTION

In 4-wire leased-line operation, if both units have autodial backup enabled, one must be configured for forced answer. This prevents both units from dialing if the leased line fails.

Both methods will cause the modem to dial the prestored autodial number. The originate modem will go to idle mode for 5 seconds and then initiate the call. The answer modem will remain idle while looking for a ring. The modems then connect and begin communicating over the dial-up line. If the dial connection is unsuccessful after three attempts, a retrain on the leased line will be initiated.

In manual mode, the return to leased line is only done when commanded from the front panel or AT command. In automatic mode the return to leased line is initiated after the lookback time in register S28 has elapsed. To prevent unnecessary termination of the dial-line connection, a leased-line lookback test is performed. If the leased line is not acceptable, the dial connection is resumed with a retrain. If the leased line is acceptable, the dial connection is dropped and normal leased-line mode is resumed.

When the unit attempts to return to leased line, the LCD displays LEASE LOOKBACK. If the leased line has been restored to service, data can be passed approximately 10 seconds after LEASE LOOKBACK was initiated. The LCD will continue to display LEASE LOOKBACK for slightly more than a minute. During this time the dial-line connection is maintained in case a return to dial-line operation is required. When the LCD displays ON LINE again the dial line is disconnected.

NOTE

A diagnostic test initiated during dial-backup mode will end when the modem performs a leased-line lookback.

5.13 Placing a Call

5.13.1 DIRECT CONNECT WITH A STANDARD TELEPHONE

• Lift the telephone receiver. Set the LCD to with a TALK. Wait for the dial tone.

• Dial the number of the remote site.

• When the answer tone is heard, immediately press the TALK/DATA button. The originating modem goes off hook and normal operation will begin within 30 seconds. If not, hang up and return to the first step.

• After the link is established, hang up the telephone.

CHAPTER 5: Operation

5.13.2 DIRECT CONNECT WITH AN EXCLUSION-KEY TELEPHONE

• Place the LCD in IDLE mode and the telephone in voice mode (pull the exclusion key button up). Wait for a dial tone.

• Dial the number of the remote site.

• The remote modem answers with a 2100-Hz answer tone. If the remote modem does not answer, hang up and return to the first step.

• When the answer back tone is heard, place the telephone in data mode (push the exclusion key button down).

• The originating modem goes off hook and normal operation begins within 30 seconds. If a successful connection is not established, return to the first step.

5.13.3 A

UTODIAL FROM F

RONT PANEL

• Advance the LCD to #6 on the main menu, DIAL STORED NUMBER.

• Select the number to dial and press YES to dial. Operation begins in 30 seconds. If not, press the TALK/DATA button and return to the first step.

5.13.4 A

UTODIAL WITH THE

AT C

OMMAND SET

• To dial a number—for example, 555-1212—type AT D 555-1212 and a carriage return.

• To dial a stored number type ATD Sn (n=1-9) and a carriage return.

• The modem dials the number—either pulse or tone, whichever is currently in effect—and takes the role of the originate modem.

Refer to

Section 6.7

for additional dialing commands.

5.14 Answering a Call

5.14.1 AUTOANSWER

Autoanswer by the modem is the normal configuration. Pressing TALK/DATA switches between IDLE and TALK. The modem will answer an incoming call in either mode. If TALK is selected, a telephone plugged into the telset jack will also ring.

V.32 9600 or V.32 9600 IDLE TALK

5.14.2 MANUAL ANSWER

On ring detection the modem front panel displays:

V.32 9600 RINGING

Press TALK/DATA to answer the call or enter the ATA command at the DTE.

MODEM 325 AND MODEM 325 CARD

5.15 Call Termination

5.15.1 CONDITIONS

HAT TERMINATE A CALL

The following conditions cause call termination:

• Abort Disconnect Default 30 sec. Selectable (No answer, busy 1 to 30 sec. signal, no modem, etc.)

• ATH Disconnect command.

• Loss of Carrier Selectable 100 ms to Disconnect 25.5 sec.

• Receive Long Selectable for disable Space Disconnect or 2 sec.

• DTR Disconnect Selectable for disabled or

10 ms to 2.55 sec.

• LCD Display When TALK/DATA is

pressed LCD displays DO YOU WANT TO GO TO TALK? When YES is pressed, the modem hangs up if no phone is connected or if the connected phone is not off hook. Pressing NO displays DO YOU WANT TO DISCONNECT? Pressing YES then disconnects.

• Protocol Link Reliable mode only. Establishment Failure to establish Failure reliable link.

• Protocol Inactivity Default (0) disabled. Timeout Software selectable for

disabled or 1 to 255 minutes.

• Protocol Retry 12 retransmissions of the Limit Exceeded frame.

• Signal Quality Leased line operation with

dial backup enabled. Extended loss of carrier or 4 unsuccessful retrains in 3 minutes.

• Modem power is turned off.

5.15.2 V.32 C

LEARDOWN

V.32 cleardown is a method of call termination specified in the CCITT recommendation. The cleardown method incorporates a training sequence which ends with a command to disconnect. If long-space disconnect is disabled, the cleardown sequence is activated by the ATH2 command.

CHAPTER 6: Asynchronous Operating Commands

6. Asynchronous Operating Commands

6.1 General

Most of the time, you will probably use your modem with communications software, Your software will configure the modem for you, or will offer you simple menu choices for configuring the modem. The software will also establish and maintain the communications link for you.

If you use communications software to configure and operate your modem, you can skip this chapter. However, if you intend to do your own programming, or if you want to set the modem’s configurations directly, you can use this chapter as a reference.

This chapter describes the asynchronous operating commands used to select options, test, and operate the modem. These commands are based on the AT command set and extensions. Certain options are dependent on or are restricted by the mode of operation. For example, remote DCD is not available in the V.22 bis or Bell 103 mode of operation. Refer to

Chapter 8

for V.25 bis synchronous operating

commands.

NOTE

If AT commands are accidentally disabled, refer to the section called AT Command Set Recover later in this chapter.

6.2 Command Categories

The modem offers eight major categories of command statements:

• Response • General

• Dial • Remote Configuration

• Terminal Interface • Protocol

• Test • S-registers (

Chapter 7

)

6.3 Operation Modes

During asynchronous operation the modem functions in one of three modes:

• Offline Command Mode

• Online Command Mode

• Data Mode

6.3.1 O

FFLINE COMMAND MODE

In offline command mode (generally referred to as command mode), the modem accepts commands from the computer or terminal. Commands can be entered separately or in strings to change modem options, rebuild profiles, store or change telephone numbers, and initiate or receive phone calls. There is no data communication link established in this mode.

MODEM 325 AND MODEM 325 CARD

6.3.2 ONLINE COMMAND MODE

This mode is entered from the data mode by issuing the escape command. The data communication link remains established but data transmission is suspended. The modem will now accept commands as it does in the offline command mode.

6.3.3 D

ATA MODE

The modem goes to data mode (online) after it successfully connects with a compatible modem. In data mode, the modem sends and receives data, but will not accept or execute command instructions.

Example: The modem is in the command state. The D command and phone number are used to dial a remote modem. The local modem waits to receive a signal from the remote modem. The remote modem acknowledges the call by sending a carrier signal. When the local modem receives this carrier, it leaves the command state and goes online in the data mode. At this time, both modems are using the telephone line and a communication link is established.

In online command mode, the modem can have its own command set altered or use remote

configuration to change a remote modem’s command set.

6.4 Sending Commands to the Modem

When the computer, modem, and monitor are on, an instruction can be sent to the modem telling it what function or activity to perform. The instruction, called a command statement, command string, or just command, is typed using the computer keyboard. The command statement temporarily resides in a section of memory called the command buffer.

Each command statement is made up of characters, numbers, and such keyboard symbols as the & and % signs. Commands must be written in a specific form so that the modem recognizes and follows the instruction.

6.4.1 C

REATING A COMMAND STATEMENT

Create a command statement using the following steps:

• Type AT. This is the Attention Code telling the unit a command statement follows.

• Type the command.

• Press the return key to “Enter” or send the command statement to the modem.

Here is an example of a command statement using the dial command (D).

ATD555-1212

This command statement can be read as: “Attention: Dial 555-1212.”

Another example is ATZ. This means “Attention: Execute the Z command.”

After you enter a command line, the modem returns a response indicating whether the command was accepted or giving the data requested by the command statement.

CHAPTER 6: Asynchronous Operating Commands

6.4.2 AUTOBAUD

The attention code (AT) is analyzed by the modem to determine the transmission speed, parity, and bits per character used by the DTE. This autobaud process is repeated each time the AT command prefix is sent.

6.4.3 G

UIDELINES FOR CREATING COMMAND STATEMENTS

When typing command statements, note the following:

• The attention code (AT) may be upper or lower case, but not a combination like aT.

• Return or Enter must be pressed to execute (enter) a command.

• Command statements are limited to 40 characters.

• Use the backspace or delete key to erase the last character.

Even though the initial AT code must be all upper or lower case, characters that follow can be any mix

of upper and lower case.

6.4.4 M

ONITOR DISPLAY

As commands are typed they appear on the monitor so the operator can verify the input. This is called local character echo. The echo may be turned on or off using AT commands. Refer to Local Character Echo in the GENERAL COMMANDS section of this chapter for details.

6.4.5 C

OMMAND-STATEMENT BUFFER

The modem temporarily stores up to 40 characters in a buffer memory, so that you can repeat it with the A/ command (see

Section 6.4.7

). If this limit is exceeded, the modem does not accept the command and sends an ERROR message. To correct this condition, retype the command using 40 characters or less. The AT characters and punctuation used in phone numbers do not take up space in the buffer. Also, blank characters used as spaces to help increase readability are not counted. For example, the modem reads the commands

ATD (212) 555-1212

ATD2125551212

ATD 212 555 1212

as having 11 characters each. Type the command in any of these forms.

Three things will clear the buffer: Turning the modem off, entering AT, or using the DTR reset feature.

NOTE

Phone numbers stored using AT commands are limited to 34 characters.

6.4.6 BACKSPACE KEY

Use the backspace key to change the command statement or correct errors. The backspace key allows the cursor to be moved back to the character(s) in error. The command can then be retyped from that point.

Example: ATD5551211 has been typed. To change the last 1 to 2, press the backspace key once, type 2, and press Return to execute the command.

MODEM 325 AND MODEM 325 CARD

6.4.7 REPEATING A COMMAND (A/)

This command tells the modem to repeat the last command stored in its buffer. It automatically reexecutes the command without retyping. The return key does not need to be pressed.

Example: The ATD5551212 command has been executed, and the phone is busy. To repeat the instruction type A/, but do not use AT before this command, since AT would empty the buffer and there would be no command to repeat.

6.4.8 N

UMBERED COMMANDS

Series of commands that start with the same letter are distinguished by a number called a command parameter following the letter.

For example, the M0 command selects speaker always off, M1 speaker on until carrier detected, and

M2 selects speaker always on.

In all cases, the zero (0) may be omitted. So the commands M and M0 are identical.

This manual uses the commands without the zero. The modem treats both the same but zeros count

against the buffer total.

6.4.9 G

ROUP

COMMANDS

A group of commands can be typed in a single command statement. Pressing the return key sends the entire command string to the modem, which executes each command individually in the order in which it appears in the command statement.

For example, the command statement ATQ0V0L3DT5551212 means

AT Attention.

Q0 Allow response messages to be sent.

V0 Select digit code responses.

L3 Select high volume.

DT Tone-dial 555-1212.

The modem executes the AT command followed by the Q, V, L, D, and T commands. Command statement ATQ0V0L3DT5551212 can be read: ATQVL3DT5551212. Eliminating zeros reduces the number of characters in a command statement, thereby simplifying typing and allowing more room in the buffer.

The dial D command initiates the dial process, so no other commands, only dial modifiers, can follow the D command.

CHAPTER 6: Asynchronous Operating Commands

6.5 Command Table

Table 6-1

is a listing of the AT commands used by the modem.

Table 6-1. AT Commands.

Control General Description Page Command Number

A/ Repeat last command 54

+++ Escape code 72

A Go off hook in answer mode (answer immediately) 66

D Dial 63

E Local terminal echo 72

H Hang up 73

I EPROMcheck, product revision and model 73

L Speaker volume 74

M Speaker ON/OFF control 74

O Return online 74

Q Response control 59

V Form of response messages 59

X Call-progress control 60

Y Long-space disconnect 75

Z Reset 83

&C DCD control 67

&D DTR response 68

&F Load active profile with factory settings 84

MODEM 325 AND MODEM 325 CARD

Table 6-1 (continued). AT Commands

Control Command General Description Page

Number

&G Guard tones 75

&L Line type (telephone) 76

&M Async/sync data and sync dial method 76

&P Pulse-dial make/break ratio 77

&R RTS to CTS delay 69

&S DSR control 67

&T Diagnostic tests 70

&V View configuration profiles/receive signal parameters 84

&W Store active profile 82

&X Synchronous transmit clock source 77

&Z Store phone number 84

%An Auto-reliable fallback character 89

%B Modem speed 77

%C Data compression 89

%D Disconnect buffer delay 78

%E Automatic retrain 79

%P= Remote configuration security code 85

%T Transmit test pattern 70

%T= Initiate remote configuration 86

%V Display the modem firmware version 79

%Z Select permissive or programmable mode 79

\A MNP block size 92

CHAPTER 6: Asynchronous Operating Commands

Table 6-1 (continued). AT Commands

Control Command General Description Page

Number

\B Transmit a break/set break length 93

\C Auto-reliable buffer 93

\G Modem port flow control 87

\J Constant speed interface on/off 87

\Kn Break control 90

\N Operating mode 86

\O Originate MNP link 94

\Q Serial-port flow control 88

\R Serial-port ring indicate 68

\T Inactivity timer 92

\U Accept an MNP link 94

\V Protocol result codes 93

\X XON/XOFF flow-through mode 88

\Y Switch to MNP from normal mode 94

\Z Switch to normal from MNP mode 95

*AN Controls bilateral test functions 71

*DA Selects talk or data mode 80

*DB Selects manual or automatic dial backup 80

*DG Controls bilateral test functions 71

*FB DTE fallback control 69

MODEM 325 AND MODEM 325 CARD

Table 6-1 (continued). AT Commands

Control Command General Description Page

Number

*FT Enables or disables fast train 80

*LA DTE controlled local analog loopback 71

*LB Wait for dial-backup call (leased line) 81

*LC Controls line-current disconnect 81

*LD Dial autodial number (leased line) 81

*NT Enables/disables AT command set 81

*OR Forces modem into answer or originate mode 82

*RC Number code application 61

*RD DTE controlled remote digital loopback 71

*RO Retain/restore options at disconnect 85

*TLn Leased line TX level 82

$S=x Sets an empty password location to x 47

$C=x, y Changes either password x=old, y=new 47

$C=x, - Deletes password x from memory 47

$E=x Enables security where x is either password 47

$E? Displays the current status of security (on or off) 47

$D=x Disables security where x is either password 47

$DR Reset security 47

$D? Displays the current status of security 47

$V Displays product serial number 79

CHAPTER 6: Asynchronous Operating Commands

6.6 Response Commands

The modem communicates with the operator through response messages. These appear on the monitor or a computer printout to show the result of the command or action executed. Response messages can appear as words or as numbers.

6.6.1 H

OW RESPONSE MESSAGES WORK

When an instruction is executed, the modem sends a message to the monitor showing the results of the instruction.

6.6.2 SELECTING RESPONSE

FORM (V)

V tells the modem which type of response message to show on the monitor. These messages indicate the present state of the modem and can appear as either digit or word messages. Some programming situations require digit response messages. Otherwise, word response messages are better, because their meanings are easier to remember than digits.

Table 6-2. Selecting Response Form (V).

Command Description

V Enables digit response messages

V1 Enables word response messages†

†default

6.6.3 E

LECTING TO U

SE RESPONSE MESSAGES

The modem comes ready to send response messages which are recommended to monitor modem operation. You can change this by:

• Using the Q command

• Using the X command

• Using the \V command (refer to

Section 6.14.11

6.6.4 E

NABLED/DISABLED RESPONSE DISPLAYS (Q)

The Q command is used to enable or disable response messages. The modem still responds to commands when the response display is inhibited.

MODEM 325 AND MODEM 325 CARD

6.6.5 DIAL PARAMETER AND CONNECT SPEED DISPLAYS (X)

Command Description

X Dial-tone and busy-signal detection not selected. CONNECT (code 1)

response messages displayed for all speeds.

X1 Dial-tone and busy-signal detection not selected. Appropriate

CONNECT response messages or codes displayed for data rate.

X2 Dial-tone detection only selected. NO DIAL TONE message or code

appears if dial tone is not detected within 5 seconds.

X3 Busy-signal detection only selected. BUSY message or code

appears if dialed number is busy.

X4 Dial-tone and busy-signal detection selected. The appropriate

CONNECT message or code is displayed.†

†default

Table 6-3. Dial Parameter and Connect Speed Displays (X).

X followed by a dial command causes the modem to go off hook, wait the amount of time set in register S6, and dial the number. If connection is made, the modem returns a CONNECT (code 1) message to the screen regardless of the speed of connection. With a basic response, the modem will not detect a busy or no dial tone condition.

X1 followed by a dial command causes the modem to go off hook, wait the amount of time set in register S6, and dial the number. If connection is made the modem returns an appropriate CONNECT message or code to the screen. The modem will not detect a busy or no-dial-tone situation.

X2 followed by a dial command causes the modem to go off hook and wait for a dial tone before dialing. If a dial tone is not detected within 5 seconds, the modem sends a NO DIALTONE message and hangs up. The modem will not detect a busy situation in this mode.

X3 followed by a dial command causes the modem to go off hook, wait the amount of time set in register S6 and dial the number. If a busy signal is detected, the modem sends a BUSY message and hangs up. If the call is completed, the appropriate CONNECT message similar to X1 will be displayed. The modem will not detect a no-dial-tone situation.

X4 followed by a dial command causes the modem to go off hook and wait for a dial tone before dialing. If a dial tone is not detected within 5 seconds, the modem returns a NO DIALTONE message and hangs up. If a busy signal is detected, the modem returns a BUSY message and hangs up. If the call is completed, the appropriate CONNECT message similar to X1 will be displayed.

The X4 command combines all the features of X2 and X3. The factory setting is X4.

CHAPTER 6: Asynchronous Operating Commands

NOTE

When an X2, X3, or X4 command is in effect, an appropriate CONNECT data-rate message or code is displayed as for X1.

When a blind-dial command (X, X1, X3) is in effect, the modem waits 2 seconds or the time set by S6 and then dials.

6.6.6 N

UMBER CODE APPLICATION (*RC)

Some communications software packages use different number codes to indicate the data rate of the serial port. This option selects either of two commonly used number code sets.

Table 6-4. Number Code Application (*RC).

Command Code Set Number Operation

*RC Standard 15 4800 bps†

18 9600 bps

*RC1 Alt 11 4800 bps

12 9600 bps

†default is *RC

NOTE

Asterisks in AT commands are part of the command and do not indicate footnotes.

MODEM 325 AND MODEM 325 CARD

6.6.7 RESPONSE NUMBER CODES/MESSAGES

Response number codes, messages, and their corresponding meanings are listed in

Table 6-5

. The

connect speeds indicated are the serial-port rate (DTE), not the DCE speed.

Table 6-5. Response Codes/Messages.

Code Message Meaning

0 OK Command received.

1 CONNECT 300 bps while X1, X2, X3, or X4 command in effect.

All DTE rates while X command in effect.

2 RING Ring detected.

3 NO CARRIER Valid carrier is not detected after call attempt within period

specified by register S7, or carrier lost for value of S10 or more.

4 ERROR Command not recognized or too long.

5 CONNECT 1200 Connection made at 1200 bps.

6 NO DIAL TONE No dial tone detected for 5 seconds (X2 or X4 command in effect).

7 BUSY Dialed number busy (X3 or X4 command in effect).

10 CONNECT 2400 Connection made at 2400 bps.

11, 15 CONNECT 4800 Connection made at 4800 bps.

12, 18 CONNECT 9600 Connection made at 9600 bps.

14 CONNECT 19200 Connection made at 19200 bps.

20 CONNECT 300/REL MNP 300 bps connection.

22 CONNECT 1200/REL MNP 1200 bps connection.

23 CONNECT 2400/REL MNP 2400 bps connection.

24 CONNECT 4800/REL MNP 4800 bps connection.

25 CONNECT 9600/REL MNP 9600 bps connection.

26 CONNECT 19200/REL MNP 19200 bps connection.

NOTE: Indicated speed is DTE speed.

CHAPTER 6: Asynchronous Operating Commands

6.7 Dial Commands

Dial commands let the modem originate a call to another modem. These commands can be used with either tone- or pulse-dial telephone systems.

6.7.1 DIALING

(D)

To dial a number—for example, 555-1212,

Enter AT D 555-1212

The modem dials the number, either pulse or tone, whichever is currently in effect, and takes the role

of the originate modem.

You can use spaces, hyphens, parentheses, or other punctuation except dial modifiers to make the

command line easier to read and enter. For example, these are all treated the same:

AT D 1-800-555-1212

AT D 1 (800) 555-1212

ATD18005551212

The dial modifiers are shown in Table 6-6.

Table 6-6. Dial Modifiers.

Modifier Operation

T Tone dialing†

P Pulse dialing

’ Insert a long pause (2 seconds or value in S8)

W Wait for 2nd dial tone

! Flash (1⁄2 second)

R Switch to answer mode after dialing

@ Wait for silence

; Return to command mode after dialing

S Dial stored command line or number

†default

MODEM 325 AND MODEM 325 CARD

6.7.2 TONE DIALING (T)

To tone-dial a number sequence, insertaTinthedial command.

Enter AT D T 323-1111

In this example, the modem tone-dials the telephone number. The dialing method selected remains in effect until changed.

6.7.3 P

ULSE DIALING (P)

To pulse-dial a number sequence, insertaPinthedial command.

Enter AT D P 555-9902

6.7.4 I

NSERT PAUSE

(,)

To insert a pause in the dialing sequence, use a comma. This inserts a 2-second delay (or the value in register S8).

Enter ATDP9,1-800-555-1000

Here the modem pulse dials a 9, pauses for the telephone system to switch to an outside line, then dials the phone number. Comma pauses may be inserted consecutively if you need a longer pause.

6.7.5 W

AIT FOR SECOND DIAL TONE (W)

To wait for second dial tone

Enter ATD9W323-8000

Instead of using a comma pause for an outside line, you can wait up to 30 seconds (time specified by S7) for a second dial tone.

6.7.6 S

WITCH HOOK (!)

To flash the switchboard, enter an exclamation mark. This inserts a

⁄2

-second on-hook condition, usually

for transferring a call or similar use.

ATDT9W323-8000 ,!,, #7 377

In this example, the modem tone dials a 9, waits for the second dial tone, dials the phone number, pauses, flashes to start the transfer, pauses twice, then uses #7 to transfer the call to extension 377.

6.7.7 S

WITCHING TO ANSWER MODE AFTER DIALING (R)

To switch to answer mode after dialing, use an R at the end of the dial sequence.

AT D 555-2345 R

Use this command suffix to call an originate-only modem.

6.7.8 W

AIT FOR 5 SECONDS OF SILENCE (@)

To wait for 5 seconds of silence (no answer tone) after accessing an electronic service, use the @ command.

AT D 399-4700 @ 2251 ;

In this example the modem dials the number and, after the connection, waits for 5 consecutive seconds of silence. The modem then sends service code 2251 and returns to command mode (see the next section) for further input.

CHAPTER 6: Asynchronous Operating Commands

For example, you might enter a dollar amount for a banking transaction by entering

AT D 1400 ;

This sends the sequence 1400 and then returns to the command mode for further entries, according to

the requirements of the banking service.

6.7.9 R

EMAINING IN COMMAND

MODE (;)

To remain in command mode after dialing, place a semicolon at the end of the dial string.

AT D 234-5678 ;

The modem will dial the telephone number entered but will not attempt to train when the remote

service answers the call.

This is used to retain control so that further tones may be entered with

AT DTn ;

The semicolon should be placed at the end of each sequence of digits in order to remain in command

mode (n=additional tones to be sent).

6.7.10 DIALING A STORED TELEPHONE COMMAND LINE (S)

Use the S command to dial a previously stored command line.

ATDS—Dials number stored at location 1. ATDS and ATDS1 are the same.

To dial one of the multiple stored numbers, enter ATDSn, where n is between 1 and 9.

ATDS9

In this example the number stored in location 9 is dialed.

AT*AUn—Selects stored number n (n=1 to 9) to be autodialed. This is the autodial number, which is

used for dial backup or if DTR-controlled dialer is enabled.

6.7.11 VOICE CALLS

To make a voice call, place modem in TALK mode by pressing the TALK / DATA button and dial the number with the telephone. If you wish to use the dial command for the call

Enter AT D (number) ;

Then place the modem in TALK mode to give the telephone control of the phone line. The semicolon character (;) recalls the command mode and prevents the modems from training. The remote site must be answered by the phone with the modem in talk mode.

6.7.12 SWITCH FROM VOICE TO DATA

After dialing in TALK mode, place the modems in DATA mode by pressing the TALK/DATA button.

MODEM 325 AND MODEM 325 CARD

6.8 Answering a Call

There are three ways to answer a call for data connection:

• Manual

• AT command

• Autoanswer

The most common is autoanswer.

6.8.1 M

ANUAL A

NSWER

When the phone rings, answer by changing the front-panel switch from TALK to DATA after the first ring.

6.8.2 AT COMMAND ANSWER (A)

The modem can be made to go off hook in the answer mode by entering ATA when the phone rings. This commands the modem to go to the answer mode and connect.

6.8.3 A

UTOANSWER (S0)

Autoanswer is controlled by register S0. S0 determines which ring the modem answers on. S0 can be loaded with a value between 1 and 255 for autoanswer.

Entering ATS0=0 disables the autoanswer feature. Decide which ring the modem is to answer on and

set S0 to that decimal value.

NOTE

If the &D2 option is active, the DTR signal must be on for autoanswer to work.

When these steps have been taken, the modem automatically answers on the selected ring and connects with the calling modem. This allows two computer systems to exchange data via unattended modems. Actual data transfers may be controlled by the software used by both computers.

6.9 Terminal-Interface Commands

The terminal interface is the connection between the modem and its associated data terminal (for example, your computer). Terminal-interface commands control the action of the modem and the terminal in response to the signals being exchanged on the interface.

CHAPTER 6: Asynchronous Operating Commands

6.9.1 DATA CARRIER DETECT (&C)

When using DCD to indicate a valid carrier, enter AT&C1. Some terminals and other devices require DCD on to communicate with the modem; if so, select &C.

Table 6-7. Data Carrier Detect (&C).

Command Operation

&C DCD always on†

&C1 DCD is on when the modem recognizes remote modem carrier or, if enabled,

when MNP negotiation is complete

&C2 DCD on except for 5 seconds after disconnect

&C3 DCD follows RTS on remote modem (simulated switched carrier)

†default

AT&C3 simulates switched-carrier operation.

NOTE

For simulated switched carrier-operation, &C3 must be selected on both modems. (Only available in V.32 direct or synchronous mode.)

6.9.2 D

ATA SET READY (&S)

These commands control the DSR signal generated by the modem to indicate that the modem is ready for operation. DSR must be on for some terminals and devices to communicate with the modem.

Table 6-8. Data Set Ready (&S).

Command Description

&S DSR always on†

&S1 DSR on when off hook in data mode

&S2 DSR off for 5 seconds after disconnect then returns to on

&S3 DSR follows OH (off hook)

†default

MODEM 325 AND MODEM 325 CARD

6.9.3 DATA TERMINAL READY (&D)

In data mode, DTR may be used for modem control.

Table 6-9. Data Terminal Ready (&D).

Command Description

&D Causes the modem to ignore DTR†

&D1 Causes the modem to go to command mode from data mode when

DTR goes from on to off.

&D2 Commands the modem to disconnect when DTR goes from on to off

and disables autoanswer while DTR is off.

&D3 Disconnects, recalls command mode, and resets the modem to a

stored configuration when DTR goes from on to off. In dial-line mode, the modem will disconnect; in leased-line mode, the modem will retrain.

†default

NOTE

If DTR Controls Dialer is selected, then &D1 and &D2 will cause an autodial after an off-toon transition of DTR.

6.9.4 S

ERIAL-PORT RING INDICATE (\R)

Determines indication mode of serial-port ring indicate line (pin 22) and LCD display.

Table 6-10. Serial Port Ring Indicate (\R).

Command Operation

\R Causes the LCD ring-indicate display and EIA-232 pin 22 to turn on

(high) when the phone rings and remain on during the duration of the call.

\R2 Causes the LCD ring-indicate display and EIA-232 pin 22 to turn on

(high) when the phone rings and turn off (low) when the call is answered.†

†default

CHAPTER 6: Asynchronous Operating Commands

6.9.5 REQUEST TO SEND/CLEAR TO SEND (&R)

When the modem is operating in nonbuffered mode (direct mode), AT&R enables the RTS-to-CTS delay, determined by the value in S26. AT&R1 forces CTS high, and the modem ignores RTS. With AT&R2 selected, CTS goes high when carrier is detected. AT&R9 forces CTS to follow the state of RTS without delay.

Table 6-11. Request to Send/Clear to Send (&R).

Command Description

&R Enables RTS to CTS delay

&R1 CTS forced on†

&R2 CTS follows DCD

&R3 CTS equals RTS

†default

NOTE

RTS/CTS delay is not valid in buffered mode or with MNP enabled.

NOTE

With AT&R2 selected, XON/XOFF is the only valid method of flow control and &C and &C1 are the only valid carrier detect options.

6.9.6 DTE F

ALLBACK (PIN 23) (*FB)

If the DTE fallback (EIA-232, pin 23) input to the modem is not in use, set the option to ignore pin 23. To cause the modem to act on high/low levels of pin 23, enable this option. Negative level forces higher rate; positive forces lower rate.

Table 6-12. DTE Fallback (Pin 23) (*FB).

Command Operation

*FB Ignore pin 23†

*FB1 Transition on pin 23 changes speed

†default

MODEM 325 AND MODEM 325 CARD

6.10 Test Commands (&T)

Diagnostic tests are used to isolate faults in the communications path. Diagnostic tests will terminate after the period of time specified by S18. If S18 is set to 0, the timer is disabled and tests will run continuously. Tests may also be terminated by the AT&T command. When in test modes without test pattern, issue the escape sequence (+ + +) to return to command mode before terminating the test with the AT&T command.

Table 6-13. Test Commands (&T).

Command Operation

&T Terminate any test

&T1 Initiate local analog loopback test

&T2 Initiate remote analog loopback test

&T3 Initiate local digital loopback test

&T4 Allows acceptance of remote requested digital loopback†

&T5 Disallows acceptance of remote requested digital loopback

&T6 Initiate remote digital loopback test

&T7 Initiate remote digital loopback with test pattern

&T8 Initiate local analog loopback test with test pattern

&T9 Initiate remote analog loopback with test pattern

%T Transmit test pattern

†default

NOTE

Local analog loopback with or without test pattern is the only test available in error-control mode.

CHAPTER 6: Asynchronous Operating Commands

6.10.1 BILATERAL TEST ENABLE/DISABLE (*AN, *DG)

Enables or disables bilateral test function.

Table 6-14. Bilateral Test Enable/Disable.

Command Operation

*AN Bilateral analog loop disabled† *AN1 Bilateral analog loop enabled

*DG Bilateral digital loop disabled† *DG1 Bilateral digital loop enabled

†default

6.10.2 DTE-CONTROLLED REMOTE DIGITAL LOOPBACK (PIN 21) (*RD)

To enable DTE-controlled remote digital loopback, enter AT*RD1. When the test is enabled, the modem goes into remote digital loopback when it detects an off-to-on transition of pin 21 while in the online data mode. The test ends when it detects an on-to-off transition of pin 21 and then returns to online data mode. To disable this function, enter AT*RD.

Table 6-15. DTE Controlled Remote Digital Loopback (Pin 21) (*RD).

Command Operation

*RD Ignore pin 21†

*RD1 RDL enabled (pin 21)

†default

NOTE

If the test timeout option is enabled and pin 21 remains high, the modem returns to online mode at the end of the test timeout period and then immediately reenters the test mode.

6.10.3 DTE-C

ONTROLLED LOCAL ANALOG LOOPBACK (PIN 18) (*LA)

To enable DTE-controlled local analog loopback, enter AT*LA1. When the test is enabled, the modem goes into local analog loopback when it detects an off-to-on transition of pin 18. The test ends when it detects an on-to-off transition of pin 18. To disable the test, enter AT*LA.

MODEM 325 AND MODEM 325 CARD

Table 6-16. DTE Controlled Local Analog Loopback (Pin 18) (*LA).

Command Operation

*LA Ignore pin 18†

*LA1 LAL enabled (pin 18)

†default

NOTE

If the test timeout option is enabled and pin 18 remains high, the modem returns to idle mode at the end of the test timeout and then immediately reenters the test mode.

6.11 General Commands

These commands control various standard options that in most cases apply to any mode of operation.

6.11.1 C

HANGING FROM

DATA

MODE TO COMMAND MODE (+ + +)

To change from data mode to online command mode, press the escape character three times (+ is the default). Pause for the length of time set by register S12 (1 second is the default) before and after the +++ to ensure the modem recognizes the escape command.

This sequence temporarily suspends data mode transmissions and allows command mode operations without breaking the connection. The modem responds with OK when it detects the escape code. Return to data mode by entering ATO.

NOTE

The AT command set must be enabled.

6.11.2 LOCAL CHARACTER ECHO (E)

Type AT without a carriage return. If the screen shows AT, the character echo is set correctly. Proceed with other commands as desired.

If the screen shows AATT, enter the ATE command to correct the double characters, or disable the local echo on the terminal.

If the screen shows no characters, type ATE1 to turn the echo on, or enable local echo on the terminal.

CHAPTER 6: Asynchronous Operating Commands

Table 6-17. Bilateral Test Enable/Disable.

Command Operation

E Echo off

E1 Echo on†

†default

6.11.3 HANGING UP (H)

To terminate a call, enter the command ATH. This tells the modem to disconnect and go on hook. The modem must be in command mode to use this command.

6.11.4 V.32 C

LEARDOWN (H2, H3)

This disconnect option allows a training sequence before the actual hang up.

Table 6-18. V.32 Cleardown (H2, H3).

Command Operation

H2 V.32 cleardown enabled

H3 V.32 cleardown disabled†

†default

6.11.5 EPROM CHECK

(I)

PC software packages may issue the ATI command to verify the modem will support all commands needed by the software package. The modem returns ASCII characters representing the model and revision level. To request the CRC to be calculated on the EPROM, enter ATI1. The modem returns four ASCII characters representing the CRC in hexadecimal form. Enter ATI3 to request the product version.

Table 6-19. EPROM Check (I).

Command Operation

I Request product code

I1 Request EPROM CRC value

I3 Request product version

MODEM 325 AND MODEM 325 CARD

6.11.6 SPEAKER VOLUME (L)

ATL commands offer three volume levels.

Table 6-20. Speaker Volume (L).

Command Operation

L, L1 Speaker volume low

L2 Speaker volume medium†

L3 Speaker volume high

†default

6.11.7 SPEAKER CONTROL (M)

ATM commands enable or disable the speaker for monitoring purposes.

Table 6-21. Speaker Control (M).

Command Operation

M Disables the speaker

M1 Disables the speaker while receiving a carrier signal†

M2 Speaker always on

M3 Disables the speaker while receiving a carrier signal and modem is dialing

†default

6.11.8 RETURN ONLINE (O)

Use the O command when you are in the online command mode and want to return to data mode. It returns the modem to the same mode (originate or answer) that it was in before escaping to the (online) command mode.

CHAPTER 6: Asynchronous Operating Commands

6.11.9 LONG SPACE DISCONNECT (Y)

One method of disconnecting two modems is called long-space disconnect. When any disconnect condition is detected by the local modem, it will send 4 seconds of data space condition to the remote modem before disconnecting. This signals the remote modem to disconnect. The local modem will disconnect if it receives 1.6 or more seconds of data space condition from a remote modem. If break sequences of 1.6 or more seconds are to be sent, enter ATY to disable this feature and prevent unintentional disconnects.

NOTE

This option must be disabled if SDLC NRZI data is used.

Table 6-22. Long Space Disconnect (Y).

Command Operation

Y Long space disconnect off

Y1 Long space disconnect on†

†default

6.11.10 GUARD TONES (&G)

This option controls the generation of CCITT V.22 guard tones. These guard tones are not used in the United States.

Table 6-23. Guard Tones (&G).

Command Operation

&G No guard tone†

&G1 550 Hz guard tone

&G2 1800 Hz guard tone

†default

MODEM 325 AND MODEM 325 CARD

6.11.11 DIAL/LEASED LINE (&L)

If operating on dial-up lines, enter AT&L. If operating on leased lines, enter AT&L1 for 2-wire or AT&L2 for 4-wire.

Table 6-24. Dial/Leased Line (&L).

Command Operation

&L Dial (switched)†

&L1 Leased (private) 2-wire

&L2 Leased (private) 4-wire

†default

6.11.12 ASYNCHRONOUS/SYNCHRONOUS MODE SELECTION (&M)

The AT&M commands select synchronous or asynchronous operation and V.25 bis autodialing protocols.

AT&M selects asynchronous mode.

AT&M1 selects synchronous mode 1. Calls are placed asynchronously. Operation switches to synchronous when connecting.

AT&M2 selects synchronous mode 2. The modem automatically dials a stored number when it detects an off-to-on transition of DTR. Use the AT&Dn command to select the action to be taken on a DTR transition.

AT&M3 selects synchronous mode 3. Calls are placed manually.

AT&M4 selects synchronous mode 4. V.25 bis autodialer set for Bisync protocol.

AT&M5 selects synchronous mode 5. V.25 bis autodialer set for SDLC protocol.

Use register S30 to select EBCDIC/ASCII and NRZ/NRZI for data format.

Table 6-25. Asynchronous/Synchronous Mode Selection (&M).

Command Operation

&M Asynchronous mode†

&M1 Synchronous mode 1

&M2 Synchronous mode 2

&M3 Synchronous mode 3 (V.25 bis disabled)

&M4 Synchronous mode 4 with V.25 bis Bisync

&M5 Synchronous mode 5 with V.25 bis SDLC

†default

CHAPTER 6: Asynchronous Operating Commands

6.11.13 MAKE/BREAK DIAL PULSE RATIO (&P)

Using AT&P, the dial pulse is on for 39% and off for 61% of one cycle. Using AT&P1, the dial pulse is on for 33% and off for 67% of one cycle.

Table 6-26. Make/Break Dial Pulse Ratio (&P).

Command Operation

&P 39%: 60% (US and Canada)†

&P1 33%: 67%

†default

6.11.14 SYNCHRONOUS TRANSMIT CLOCK SOURCE (&X)

The AT&X commands select internal, external, or receive clock as the transmit clock source.

Table 6-27. Synchronous Transmit Clock Source (&X).

Command Operation

&X Internal clock†

&X1 External clock

&X2 Receive clock

†default

6.11.15 DCE S

PEED (%B)

AT%B sets the originating DCE speed to follow the DTE speed. Two modems will not connect at a speed faster than the lower DCE speed setting of the two modems. To allow the modem to transmit data at a speed different from DTE speed, enter AT%Bn (n=1 to 6).

MODEM 325 AND MODEM 325 CARD

Table 6-28. DCE Speed (%B).

Command Operation

%B Use DTE speed

%B1 300 bps

%B2 1200 bps

%B3 2400 bps

%B4 4800 bps

%B5 9600 bps

%B6 9600 trellis†

†default

6.11.16 DISCONNECT BUFFER DELAY (%D)

Sets a delay during which the modem will process data in its transmit and receive buffers before disconnecting. When a condition exists which will cause a disconnect, the modem will attempt for n seconds to empty its buffers. When the buffers are empty or if n=0, the modem disconnects immediately.

Table 6-29. Disconnect Buffer Delay (%D).

Command Operation

%D Disconnect buffer delay disabled†

%Dn Disconnect buffer delay value (seconds)

†default

CHAPTER 6: Asynchronous Operating Commands

6.11.17 AUTO RETRAIN (%E)

This option allows the modem to automatically retrain in response to poor received signal quality without a reconnection. The modem will always respond to a retrain request from the remote modem.

Table 6-30. Auto Retrain (%E).

Command Operation

%E Disable auto retrain

%E1 Enable auto retrain†

†default

6.11.18 PRODUCT REVISION LEVEL (%V)

The %V command displays the product revision level.

6.11.19 P

RODUCT SERIAL NUMBER ($V)

The $V command displays the product serial number.

6.11.20 P

ERMISSIVE

/PROGRAMMABLE

(%Z)

For dial-up operation the modem transmitter output can be set for two different modes of operation. In permissive (RJ11 jack), transmit output level is set to -9 dBm. To set the modem for permissive mode enter AT%Z. In programmable (RJ45 jack) operation, the transmit level can be set by an external program resistor. This mode is selected with AT%Z1.

Table 6-31. Permissive/Programmable (%Z).

Command Operation

%Z RJ-11 (permissive)†

%Z1 RJ-45 (programmable)

†default

NOTE

Asterisks in AT commands are part of the command and do not indicate footnotes.

MODEM 325 AND MODEM 325 CARD

6.11.21 TALK/DATA (*DA)

The AT*DA command selects talk or data mode.

Table 6-32. Talk/Data (*DA).

Command Operation

*DA Switches modem to talk

*DA1 Switches modem to data

6.11.22 DIAL BACKUP (*DB)

Determines whether dial-backup mode will be manual or automatic.

Table 6-33. Dial Backup (*DB).

Command Operation

*DB Manual dial backup operation†

*DB1 Automatic dial backup operation

†default

6.11.23 V.32 F

AST TRAIN (*FT)

The V.32 fast-train option is used to reduce training time when operating over high-quality, limited- distance dial or 2-wire leased lines.

Table 6-34. V.32 Fast Train (*FT).

Command Operation

*FT Disable fast train†

*FT1 Enable fast train

†default

CHAPTER 6: Asynchronous Operating Commands

6.11.24 RETURN TO LEASED LINE FROM DIAL BACKUP (*LB)

On dial-up lines, *LB causes the modem to return to leased line operation from dial backup. On leased lines with forced answer enabled, *LB causes the modem to wait for a dial backup call.

6.11.25 L

INE CURRENT DISCONNECT (*LC)

Dial line operation only. The modem can be configured to disconnect upon interruption of telephone line current.

Table 6-35. Line Current Disconnect (*LC).

Command Operation

*LC Line current disconnect off

*LC1 Line current disconnect short (8 ms)

*LC2 Line current disconnect long (90 ms)†

†default

6.11.26 MANUAL DIAL BACKUP (*LD)

Leased line operation only. *LD dials the autodial number if the modem is in originate mode with manual dial backup selected.

6.11.27 D

ISABLE

AT COMMAND

SET (*NT)

AT*NT disables the AT command set.

AT*NT1 allows a remote modem to enable AT command operation of another modem via remote

configuration.

Recover AT commands via LCD if needed.

Table 6-36. Disable AT Command Set (*NT).

Command Operation

*NT Disable AT command set

*NT1 Enable AT command set†

†default

MODEM 325 AND MODEM 325 CARD

6.11.28 ANSWER/ORIGINATE (*OR)

Forces modem to answer or originate mode. This option is used with 2 or 4-wire leased line operation with error correction and/or dial backup.

Table 6-37. Answer/Originate (*OR).

Command Operation

*OR Force originate†

*OR1 Force answer

†default

6.11.29 LEASED-LINE TRANSMIT LEVEL (*TLN)

Table 6-38. Leased-Line Transmit Level (*TLn).

Command Operation

*TLn Sets leased line TX level to n where n is a number between 0 and 15

corresponding to a TX level of 0 to -15 dBm

default is 0 dBm

6.12 Configuration Commands

These commands recall various profiles and insert them into the active profile, store the active profile and telephone numbers in nonvolatile memory, and designate the powerup profile. Remote configuration is discussed at the end of this section.

6.12.1 M

ODEM POWER

-ON C

ONFIGURATION (&W)

The &W command stores the current modem configuration (or profile) options in nonvolatile memory. The stored configuration is retained in memory, even when power is off, until &W is issued with a new configuration or a factory configuration is restored with the &Fn command.

To store the current configuration, enter AT&W.

When the modem is reset with the Z command or power is turned on, the stored configuration becomes the current configuration. Once a proven configuration is established, this command saves time.

To reset the modem, enter ATZ.

Enter the ATZ command to reset the modem and reinstate the power-on configuration stored in the modem memory.

Figure 6-1

illustrates configuration storage and recall.

CHAPTER 6: Asynchronous Operating Commands

Figure 6-1. Configuration Storage and Recall.

To view the active configurations, enter AT&V

The terminal displays the active configuration in the form of S-register values.

To insert a factory configuration, enter AT&Fn (n=1-4)

The AT&Fn command loads one of four factory settings into the active profile.

6.12.2 R

ESET TO STORED CONFIGURATION (Z)

To reset the modem to stored configuration profile, enter ATZ.

Table 6-39. Reset to Stored Configuration (Z).

Command Operation

Z Reset to last stored configuration

Factory

Profile (1-9)

S0 S1 S2

S80

Stored

in ROM

&F (1-9)

Active Profile

S0 S1 S2

S80

Stored

in RAM

&W (to store)

&Y Reset/Powerup

Z Immediate

&W1 (to store) &Y1 Powerup

Z1 Immediate

User Option Set #1

S0, S2, S7,

S9 . . . .S80

User Option Set #2

S0, S2, S7,

S9 . . . .S80

Stored in

Nonvolatile Memory

MODEM 325 AND MODEM 325 CARD

6.12.3 LOAD FACTORY OPTIONS (&F)

The AT&Fn command is used to load the factory option sets. Refer to

Appendix C

for a complete list of

each set.

Table 6-40. Load Factory Options (&F).

Command Operation

&F, &F1 Load factory option 1 (async dialup with MNP)†

&F2 Load factory option 2 (async dialup without MNP)

&F3 Load factory option 3 (sync dialup without MNP)

&F4 Load factory option 4 (sync 4-wire leased line without MNP)

†default

6.12.4 VIEW CONFIGURATION PROFILES/RECEIVED SIGNAL PARAMETERS (&V)

Allows the user to view the current configuration profile in the form of S-register values. &V1 displays the received signal parameters.

Table 6-41. View Configuration Profiles/Received Signal Parameters (&V).

Command Operation

&V Displays configuration profiles

&V1 Displays received signal parameters

6.12.5 STORING A TELEPHONE COMMAND LINE (&Z)

Nine stored phone number locations of up to 31 characters each are available in nonvolatile memory. Normally, one phone number per location is accommodated. However, a phone number longer than 31 characters will overflow into the next location. Any spaces remaining in the overflowed location cannot be used for another number. The stored phone number is retained until replaced by another number. Modem power can be turned off without affecting stored information.

Two commands can store phone numbers:

AT&Zn—Stores telephone number n, including dial modifiers, at location 1 (up to 31 digits).

AT*CNx,n—Stores telephone number n, including dial modifiers, at location x (x=1 to 9).

NOTE

Neither the AT prefix nor the D command should follow the &Z.

CHAPTER 6: Asynchronous Operating Commands

AT*ND—Displays the stored numbers (1-9).

NOTE

Phone numbers stored using AT commands are limited to 34 characters.

6.12.6 R

ETAINING/RESTORING OPTIONS (*RO)

This option is used when the modem is shared by two or more DTEs. When options are retained, the current configuration is not altered at disconnect. With options restored, the modem returns to the previously stored configuration on disconnect.

When the modem is configured for options to be restored, the following commands return OK but are

not executed:

AT*CN Store telephone number

AT&Z Store telephone number

AT&F Recall factory configuration

AT&W Store current configuration

Table 6-42. Retaining/Restoring Options (*RO).

Command Operation

*RO Retain options at disconnect†

*RO1 Restore options at disconnect

†default

6.13 Remote Configuration

6.13.1 SECURITY CODE (%P=)

A security code is used to prevent unauthorized access to remote configuration mode. The security code can be set to any value from 0 to 99999999 using the AT%P= <desired code> command.

Example: If the remote modem security code is 12345, then the local modem must include this code in the initialization string before the remote modem will respond. Default security code= <Blank>.

Table 6-43. Security Code (%P=).

Command Operation

%P= Sets security code to value entered after equals character.

Example: %P=<0 to 99999999>

%P? Request local security code to be displayed

%P=D When the security code equals D, access for remote configuration by a

remote modem is not possible

MODEM 325 AND MODEM 325 CARD

6.13.2 REMOTE CONFIGURATION (%T=)

This mode of operation allows the modem user to view or modify the option set of a remote modem. Entering AT%T= (security code of remote) will initiate remote configuration.

Refer to

Chapter 5

for description.

Table 6-44. Remote Configuration (%T).

Command Operation

%T= This command followed by the correct security code establishes remote

configuration mode

&T Exits remote configuration mode

6.14 Protocol Commands

These modes and conditions are selected by AT commands.

Table 6-45

illustrates mode and condition

availabilities.

Table 6-45. Operating Modes and Conditions.

Operating Error Data Flow Data Constant Mode Correction Compression Control Speed Interface

Normal Disabled Disabled Allowed Buffered On or Off

Direct Disabled Disabled Not allowed Not buffered DTE=DCE (slaved)

Reliable (MNP) Enabled On or off Allowed Buffered On

Auto-reliable Enabled On or off Allowed Buffered On (MNP)

6.14.1 OPERATING MODE (\N)

Sets the operating mode that the modem uses while in data mode. An AT\Nn command issued during command mode while a connection is in progress will not affect the current connection but will be acted on for subsequent connections. Refer to

Chapter 9

for descriptions.

CHAPTER 6: Asynchronous Operating Commands

Table 6-46. Operating Mode (\N).

Command Operation

\N Normal mode (no error control): data is buffered

\N1 Direct mode (no error control): data is not buffered

\N2 Reliable mode (MNP only)

\N3 Auto-reliable mode (try MNP then fall back to normal async)

6.14.2 SERIAL PORT (DTE) BPS ADJUST (\J)

The AT\J command allows DCE and DTE to operate at different speeds. The AT\J1 command forces serial-port (DTE) speed to follow data link speed in any mode.

If the modem is in direct mode (\J1) and a DCE link is established at a speed other than that of the original DTE autobaud speed, the modem will issue the CONNECT message for the new DTE speed at the original rate. All subsequent data will be sent to the DTE at the new DCE speed.

Table 6-47. Serial Port (DTE) bps Adjust (\J).

Command Operation

\J Disable slaved DTE/DCE (constant speed DTE on)†

\J1 Enable slaved DTE/DCE (constant speed DTE off)

†default

6.14.3 DATA-LINK FLOW CONTROL (\G)

Enables or disables flow control used to pace data sent from the remote modem to the local modem during a normal connection. When AT\G1 is set, the modem uses XON/XOFF to start/stop data transmission from the remote modem. This command is ignored during a reliable connection.

Table 6-48. Data Link Flow Control (\G).

Command Operation

\G Disable modem-port flow control†

\G1 Enable modem-port XON/XOFF flow control

†default

MODEM 325 AND MODEM 325 CARD

6.14.4 SERIAL-PORT FLOW CONTROL (\Q)

Sets the type of flow control used by the serial port. If the serial-port speed exceeds that of the modem connection, characters may be sent by the DTE to the modem faster than it can send them to the remote modem. The modem holds characters in an internal buffer until they can be transmitted. When this buffer is full, the modem uses flow control to cause the DTE to stop sending characters. As the modem continues to transmit data and the buffer empties, flow control is again used to cause the DTE to resume sending data.

AT\Q disables flow control.

When AT\Q1 is set, the modem generates and accepts XON/XOFF characters to start and stop the data

flow. These characters have the same parity as the DTE setup taken from the last AT command.

AT\Q2 allows use of CTS off to stop the data from the DTE and CTS on to restart it.

AT\Q3 forces the modem to act on CTS like \Q2. In addition, RTS on/off is used to start and stop data

from the modem to the DTE.

Table 6-49. Serial-Port Flow Control (\Q).

Command Operation

\Q Disable DTE flow control

\Q1 Enable XON/XOFF flow control†

\Q2 Enable CTS flow control

\Q3 Enable bilateral CTS/RTS flow control

†default

6.14.5 XON/XOFF PASSTHROUGH (\X)

This option is active when flow control of the modem by the DTE has been selected for XON/XOFF and the connect mode is reliable or normal. It enables or disables the sending of local flow control characters (XON/XOFF) to the remote modem. In reliable mode, the modem treats incoming XON/XOFF characters from the remote modem as data characters. In normal mode, the modem will look at the \G command and act accordingly.

CAUTION

With \X1 in effect, local flow-control characters will be sent to the remote system. These characters may turn on the flow of data from the remote system before the modem is ready to receive more data, possibly resulting in a loss of data.

CHAPTER 6: Asynchronous Operating Commands

Table 6-50. XON/XOFF Passthrough (\X).

Command Operation

\X Process but do not pass XON/XOFF characters to remote DCE†

\X1 Process and pass XON/XOFF characters to remote DCE

†default

6.14.6 MNP DATA C

OMPRESSION (%C)

To enable data compression while running MNP protocol, enter AT%C1. To disable data compression, enter AT%C.

Table 6-51. MNP Data Compression (%C).

Command Operation

%C Data compression disabled

%C1 Data compression enabled†

†default

6.14.7 AUTO-RELIABLE FALLBACK CHARACTER (%AN)

Selects the ASCII character to be recognized as the auto-reliable fallback character by the answering modem. During negotiation of protocol in auto-reliable mode, the answering modem switches from reliable to normal mode upon receipt of the auto-reliable fallback character from the calling modem and passes the character to the serial port.

To set the auto-reliable fallback character, enter AT%An, where n=1 to 127 decimal representing an ASCII character

The default of 0 disables auto-reliable fallback character.

MODEM 325 AND MODEM 325 CARD

Table 6-52. Auto-Reliable Fallback Character (%An).

Command Operation

%An Sets ASCII character to be recognized as the auto-reliable fallback character.

NOTE

The modem must be configured for auto-reliable mode (AT\N3).

6.14.8 B

REAK CONTROL (\KN)

Use AT\Kn (n =0-5) to indicate the action taken by the modem when a break is encountered.

Table 6-53. Break Control (\Kn).

Command Operation

\K Break option 0

\K1 Break option 1

\K2 Break option 2

\K3 Break option 3

\K4 Break option 4

\K5 Break option 5†

†default

Conditions under which breaks may occur are explained below with descriptions of the modem’s

response under the different \K command break options.

1. If a break is sent to the serial port while the modem is in connect state during a reliable or normal connection (no protocol, data buffered):

CHAPTER 6: Asynchronous Operating Commands

Table 6-54. Break-Control Command Effects.

Command Effect

\K, \K2, \K4 Enter command mode but do not send break to the remote modem

\K1 Empty the data buffers and send break to the remote modem

\K3 Immediately send break to the remote modem

\K5 Send break to the remote modem in sequence with any data received from

the serial port

2. If a break is sent to the serial port while the modem is in connect state during a direct connection (no protocol, data not buffered):

Table 6-55. Break-Control Command Effects.

Command Effect

\K, \K2, \K4 Immediately send a break to the remote modem and enter command state

when break is through

\K1, \K3, \K5 Immediately send a break to the remote modem

3. If a break is received from the remote modem while the modem is in connect state during a normal connection (no protocol, data buffered):

Table 6-56. Break-Control Command Effects.

Command Effect

\K, \K1 Empty the data buffers and send a break to the serial port

\K2, \K3 Immediately send a break to the serial port

\K4, \K5 Send a break to the serial port in sequence with any data received from

remote modem

MODEM 325 AND MODEM 325 CARD

4. If a transmit break command is issued while the modem is in command state during a reliable (MNP) or normal connection (no protocol, data buffered):

Table 6-57. Break-Control Command Effects.

Command Effect

\K, \K1 Empty the data buffers and send a break to the remote modem

\K2, \K3 Immediately send a break to the remote modem

\K4, \K5 Send a break to the remote modem in sequence with any data received from

the serial port

6.14.9 MAXIMUM

MNP BLOCK SIZE (\A)

Sets the maximum transmit block size for reliable connections. Use this command to force the modem to transmit smaller blocks when in a reliable connection. The modem sends a block up to the size specified by the AT\A command.

Table 6-58. Maximum MNP Block Size (\A).

Command Operation

\A Maximum transmit block size=64 characters

\A1 Maximum transmit block size=128 characters

\A2 Maximum transmit block size=192 characters

\A3 Maximum transmit block size=256 characters†

†default

6.14.10 MNP I

NACTIVITY TIMER (\T)

Specifies the number of minutes the modem will stay online in a reliable mode without transmitting or receiving data. When time is set to 0, it is disabled. The timer is active only during a reliable connection.

Table 6-59. MNP Inactivity Timer (\T).

Command Operation

\T Disable inactivity timer†

\Tn Set inactivity to n (n=1-90) minutes

†default

CHAPTER 6: Asynchronous Operating Commands

6.14.11 PROTOCOL RESULT CODES (\V)

Enables or disables protocol result codes. See

Table 6-60

Table 6-60. Protocol Result Codes (\V).

Command Operation

\V Disable protocol result codes†

\V1 Enable protocol result codes

†default

6.14.12 TRANSMIT BREAK/SET BREAK LENGTH (\B)

AT\B commands the local modem to send a break signal to the remote modem. In all modes except direct, S-register 79 determines the length of the break sent to the DTE by the modem when it receives a break signal over the link. S79 may be set directly or via AT\Bn, where n=1-255 in 20-ms increments. The default is 35 (700 ms).

Table 6-61. Transmit Break/Set Break Length (\B).

Command Operation

\B Sends a break signal to the remote modem (does not modify S79)

\Bn Sets S79 to length of break desired: n=1-255 in 20-ms increments.

Default is 35 (700 ms).

6.14.13 SET

AUTO-RELIABLE BUFFER (\C)

Determines whether or not the answering modem will buffer data received from the non-reliable originate modem during the 4-second interval the answer modem attempts to establish a reliable link. Use these commands when the modem is in the auto-reliable mode and is expected to process a non- reliable call. Refer to

Chapter 9

for information on reliable mode.

Table 6-62. Set Auto-Reliable Buffer (\C).

Command Operation

\C Disable auto-reliable data buffer†

\C1 Buffer data for 4 seconds or 200 characters

†default

MODEM 325 AND MODEM 325 CARD

6.14.14 ORIGINATE MNP LINK (\O)

The AT\O command forces the local modem to return online and initiate a MNP link regardless of whether it originated or answered the call. For this command to succeed, the remote modem must have received the AT\U command. The modem sends two link requests (18 seconds); if the remote modem does not respond, the modem returns to normal mode.

Table 6-63. Originate MNP Link (\O).

Command Operation

\O Originate a reliable link

6.14.15 ACCEPT AN

MNP LINK (\U)

Forces the modem to return online and accept a reliable link independent of whether the modem originated or answered the call. For this command to succeed, the remote modem must have received the AT\O command.

This command will cause the modem to wait indefinitely for the remote modem to issue the “originate

MNP link” command.

Table 6-64. Accept an MNP Link (\U).

Command Operation

\U Accept an MNP link

6.14.16 SWITCH FROM

NORMAL TO MNP (\Y)

Entering \Y causes the modem to return online and attempt a reliable link while connected in normal or direct mode. If the modem was in originate mode for the call, it will initiate a reliable link; if it was in answer mode, it will accept a reliable link from the remote modem. The remote modem must switch to reliable mode for this command to succeed. The modem will return to a normal connection if a reliable link is not established in 18 seconds.

Table 6-65. Switch from Normal to MNP (\Y).

Command Operation

\Y Switch from normal to MNP

CHAPTER 6: Asynchronous Operating Commands

6.14.17 SWITCH FROM MNP TO NORMAL (\Z)

This command causes the modem to return online and switch from a reliable connection to a normal connection.

Table 6-66. Switch from MNP to Normal (\Z).

Command Operation

\Z Switch from MNP to normal

NOTE

If \J1 and \C are set, the \Z command forces the modem to the direct mode.

MODEM 325 AND MODEM 325 CARD

7. Status Registers

Most users can skip this chapter. Your communications software, or the AT commands described in

Chapter 6

, will be enough to configure your modem for everything you need it to do.

However, manipulating the status registers (usually called “S-registers”) directly gives programmers more sophisticated capabilities. This chapter explains what the S-registers are and how to use them to change the configuration of the modem.

7.1 How S-Registers Work

The S-registers hold all the modem’s configuration information. When you send—or your software sends—an AT command to change the configuration, the AT command changes a number in one of the S-registers.

You can also change the S-registers directly by “writing” to them—using ATS commands to change the numbers stored in the registers. Except for certain “read-only” registers, which cannot be changed by ATS commands, every S-register can be manipulated this way.

See

Appendix D

for a complete list of the modem’s S-registers.

Bit values for S-registers must not be confused with the total register value. In some S-Registers, bit values are counted separately for each option group (a technique called bit-mapping), while the register value is the cumulative decimal or hexadecimal total. The decimal value counts all eight bits as a single group. Hexadecimal values split the bits into two groups of four each. Writing to an S-register changes the total value.

Figure 7-1

illustrates the difference between decimal calculation and hexadecimal calculation.

Bit 7 6 5 4 3 2 1 0 Decimal Value 128 64 32 16 8 4 2 1 S22 Value 0 1 0 0 0 1 1 0 Decimal Total 64 + 4 + 2 = 70 Hexadecimal Value 8 4 2 1 8 4 2 1 S22 Value 0 1 0 0 0 1 1 0 Hexadecimal Total 4 and 4 + 2 = 46

Figure 7-1. Calculating S-Register Values.

CHAPTER 7: Status Registers

7.2 S-Register Operation

To read a register value:

Enter ATSn? (n=register number) for decimal value

or ATSn?^ for hexadecimal value

For example, to determine the current backspace character

Enter ATS5?

The screen will show the ASCII value of the backspace character stored in register S5.

To change (write to) a register value:

Enter ATSn=v (n=register number, v=decimal value)

or ATSn=^v (^v=hexadecimal value)

NOTE

Not all registers can be set by the ATSn=v (or ^v) command. Remember that some registers are read-only.

To change the escape character from + to the ESC key (ASCII value of 27):

Enter ATS2=27

To return the modem to the command mode press the ESC key three times:

(pause) ESC ESC ESC (pause)

7.2.1 I

NDIVIDUAL BIT COMMAND (SN .(BIT#) = V)

Most operators use AT commands as the primary method of changing S-register options. However, some options stored in registers do not have an associated AT command. For these options, an individual bit AT command can be used to change the setting of the bit controlling the option.

To change a single bit value within a register:

Enter ATSn . (bit#) = v, where n= register number, v= bit value 1 or 0

Example:

S-register 27, bit 2 selects dial-up or leased-line operation.

• AT command method: AT&L selects dial-up operation (sets S27 bit 2 to 0) AT&L1 selects leased-line operation (sets S27 bit 2 to 1)

• Individual bit method: ATS27.2=0 selects dial-up operation (sets S27 bit 2 to 0) ATS27.2=1 selects leased line operation (sets S27 bit 2 to 1)

MODEM 325 AND MODEM 325 CARD

NOTE

This method of option selection can be used on all S-registers except read-only registers.

7.2.2 AUTOANSWER (S0 = 0-255)

This register turns autoanswer on or off. Set the register to 0 to turn autoanswer off.

Set the register to any nonzero (1-255) value to turn autoanswer on. The number selected is the ring count the modem answers on. For example, if S0 equals 4, the modem answers the call on the fourth ring. The default value is 1.

7.2.3 R

ING COUNT (S1 = 0-255)

This register contains the ring count for each incoming call. There is no need to change its value since it is reset by each call or if no rings occur after 8 seconds. If you are developing communications software, you can have the program read the register to determine the ring total.

7.2.4 E

SCAPE CHARACTER (S2 = 0-255)

The standard escape character is a + sign (ASCII value of 43). To change the character, set S2 to the desired ASCII value.

To disable the escape command, set S2 to any value greater than 127.

7.2.5 E

ND-OF-LINE CHARACTER (S3 = 0-127)

The standard character is the carriage return (ASCII value of 13). This character ends each command as it is sent to the modem. It is also sent by the modem after each status message or number code.

To change the character, set S3 to the desired ASCII value (0-127).

7.2.6 L

INE-FEED CHARACTER (S4 = 0-127)

The standard character is the line feed (ASCII value of 10). This character is sent by the modem after each status message. To change it, set S4 as desired (0-127).

7.2.7 B

ACKSPACE CHARACTER

(S5 = 0-127)

The standard character is the backspace (ASCII value of 8). To change it, set S5 to the desired value (0-127).

7.2.8 P

AUSE BEFORE DIALING (S6 = 0-255)

When dial tone detection is disabled (command X, X1, or X3 in effect), the modem waits the number of seconds (0-255) stored in this register before dialing. The default value is 2 (seconds).

7.2.9 P

AUSE FOR RINGBACK DETECTION/PAUSE FOR CARRIER DETECTION (S7 = 1-30)

If no ringback is detected in the number of seconds in S7 (1-30), the modem disconnects and sends the NO CARRIER message or code. If ringback is detected, the modem begins to look for a carrier.

If no carrier is detected within the number of seconds in S7, the modem hangs up and sends the NO CARRIER message or code.

Values between 1 and 30 may be used. The default value is 30 (seconds).

CHAPTER 7: Status Registers

7.2.10 PAUSE INTERVAL FOR COMMA (S8 = 0-255)

When a dial command contains a comma, the modem pauses the number of seconds in S8. Change S8 to change the basic pause interval (0-255), or use several commas in a row for greater delay during dialing.

The default value is 2 (seconds).

7.2.11 C

ARRIER DETECT TIME (S9 = 0-255)

Amount of time (0-255) in 0.1-second increments the carrier must be present to be recognized. The default value is 6 (0.6 second). Data Carrier Detect (DCD) will be raised when carrier is recognized. This timer can be extended to lessen the likelihood of false detection of carrier.

7.2.12 L

OST CARRIER D

ETECT TIME

(S10 = 0-255)

Amount of time (0-255) in 0.1-second increments needed to recognize the loss of carrier. Data carrier detect (DCD) will be dropped when the loss of carrier is recognized and the modem disconnects. The default value is 14 (1.4 seconds).

NOTE

If S10 is less than S9, any loss of carrier results in a disconnect. When S10 is larger than S9, the length of time that a carrier loss can be tolerated is the difference between S10 and S9.

7.2.13 DTMF T

ONE DURATION (S11)

Determines the length of DTMF tones in 1-ms increments. The period of silence is equal to the duration of the tone. The value of this register must be entered in multiples of 10. Default value is 80 (80 ms).

7.2.14 E

SCAPE SEQUENCE

PAUSE INTERVAL (S12 = 0-255)

Using the escape sequence to return to command mode from data mode requires two pauses, one before and one after the escape characters.

The pauses prevent the modem from responding to a character sequence which might contain the

escape sequence as part of its normal data transmission.

S12 contains the pause interval in 0.02-second increments. The factory setting is 50, equivalent to 1

second (50 x 0.02 sec). When S12 is 0, timing is not a factor.

The timing between the three escape characters must be less than the pause interval, or the escape sequence will not be detected. The data rate also affects the timing and must be taken into account when changing the pause interval.

To disable the escape command, set S2 to a value greater than 127 instead of changing S12. Values between 0 and 255 may be used for S12.

7.2.15 S13

Not used

NOTE

When S-registers have parallel AT commands, the commands are listed in the register tables as a cross reference. If no command exists for the option, the column is left blank.

MODEM 325 AND MODEM 325 CARD

100

7.2.16 S14 (BIT-MAPPED OPTIONS)

Table 7-2. S14 (Bit-Mapped Option).

Bit Value Command Description

0 — — Reserved

1 0 E Local character echo off

†1 E1 Local character echo on

2 †0 Q Response displays on

1 Q1 Response displays off

3 0 V Response digit messages

†1 V1 Response word message

4 †0 Ignore

1 Q2 Response display on in originate mode only

5 †0 T Tone dial

1 P Pulse dial

6 0 H2 V.32 cleardown enabled

†1 H3 V.32 cleardown disabled

7 0 *OR1 Forced answer

†1 *OR Normal answer

†default

NOTE

If status bits are of interest, read the register value to find which bits are set.

7.2.17 S15

Not used

CHAPTER 7: Status Registers

101

7.2.18 SYSTEM TESTS (S16)

Contains the status of system-test settings.

Table 7-3. System Tests (S16).

Bit Value Command Description

0 0 — Analog loopback inactive

Analog loopback in progress

1 — — Reserved

2 0 Digital loopback inactive

1 Digital loopback in progress

3 0 Slaved digital loopback inactive

1 Slaved digital loopback in progress

4 0 Remote digital loopback inactive

1 Remote digital loopback in progress

5 0 Self test remote digital loopback inactive

1 Self test remote digital loopback in progress

6 0 Self test analog loopback inactive

1 Self test analog loopback in progress

7 — — Reserved

7.2.19 S17

Not used

MODEM 325 AND MODEM 325 CARD

102

7.2.20 TEST TIMEOUT (S18)

Amount of time (0-255), in 1-second increments, that a diagnostic test will run. A value of 0 disables the timer. The default value is 0.

7.2.21 S19, 20

Not used

7.2.22 S21 (B

IT-MAPPED O

PTIONS)

Table 7-4. S21 (Bit-Mapped Options).

Bit Value Command Description

6, 0 †00 &S DSR always on

10 &S1 DSR on when off hook in data mode 01 &S2 DSR off 5 seconds after disconnect 11 &S3 DSR follows off hook (OH)

5, 1 †00 &C DCD always on

10 &C1 DCD follows carrier from remote modem 01 &C2 DCD on except for 5 seconds after disconnect 11 &C3 DCD follows RTS on remote modem; in reliable mode follows

carrier only

2 0 &R CTS follows RTS by S26 delay

†1 &R1 CTS always on

4, 3 †00 &D DTR ignored

01 &D1 DTR on/off transition recalls asynchronous command state 10 &D2 DTR on/off transition causes disconnect 11 &D3 DTR on-to-off transition disconnects and resets modem to

current stored configuration

7 0 Y Long space disconnect disabled

†1 Y1 Long space disconnect enabled

†default

CHAPTER 7: Status Registers

103

7.2.23 S22 (BIT-MAPPED OPTIONS)

Table 7-5. Bit Mapped (S22).

Bit Value Command Description

1, 0 00 L Speaker volume low

01 L1 Speaker volume low †10 L2 Speaker volume medium 11 L3 Speaker volume high

3, 2 00 M Speaker off

†01 M1 Speaker on until carrier detect 10 M2 Speaker always on 11 M3 Speaker off when modem is dialing

6, 5, 4 000 X CONNECT message only, blind dials, no busy detect

001 X1 CONNECT/appropriate code for rate, blink dials, no busy

detect

010 X2 CONNECT/appropriate code for rate, waits for dial tone, no

busy detect

011 X3 CONNECT/appropriate code for rate, blind dials, reports

BUSY

†100 X4 CONNECT/appropriate code for rate, waits for dial tone,

reports BUSY

7 †0 &P Make/break ratio (US) 39/61

1 &P1 Make/break ratio (UK) 33/67

†default

7.2.24 S23 (BIT-MAPPED OPTIONS)

Table 7-6. S23 (Bit-Mapped Options).

Bit Value Command Description

0 0 &T5 Remote digital loopback disabled

†1 &T4 Remote digital loopback enabled

5-1 — — Reserved

7, 6 †00 &G No guard tone

01 &G1 550-Hz guard tone 10 &G2 1800-Hz guard tone 11 — Not used

†default

Black Box MD278A, MD278A-R2, MD278C User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual