Courier 56K Business Modem Command Reference

Technical Information

Your modem uses multiple standard data communications protocols and is also compatible with many nonstandard schemes. The following schemes are supported:

Modulation
Error Control, Data Compression, Testing, and Dialing
Fax
Specifications
Serial Ports
The EIA-232 Interface
Wiring a DB-25 to DB-9 Cable
Minimum Requirements
Flow Control Requirements

Modulation

This modulation	Supports
V.90 and V.92	ITU 56K standard, server capabilities. 56 through 28 kbps; Pulse Coded Modulation (PCM).
ITU-T V.34	33.6/31.2/28.8/26.4/24/21.6/19.2/16.8/14.4/12 kbps; 9600/7200/4800 bps asynchronous Trellis Coded Modulation (TCM)
V.FC	28.8/26.4/24/21.6/19.2/16.8/14.4 kbps asynchronous TCM
V.32 terbo	21.6/19.2/16.8/14.4/12 kbps; 9600/7200 bps asynchronous TCM; 4800 bps asynchronous Quadrature Amplitude Modulation (QAM)
HST	16.8/14.4/12 kbps; 9600/7200 bps asynchronous, asymmetrical, 450 bps back channel with automatic handshake adjustment to 300 bps TCM and QAM; 4800 bps asynchronous, asymmetrical, 450 bps back channel with automatic handshake adjustment to 300 bps QAM.
ITU-T V.32 bis	14.4/12 kbps; 9600/7200 bps asynchronous TCM; 4800 bps asynchronous QAM
ITU-T V.32	9600 bps asynchronous, TCM; 4800 bps asynchronous, QAM
ITU-T V.22 bis	2400 bps asynchronous, QAM
Bell 212A	1200 bps (also V.22) asynchronous, Differential Phase Shift Keying (DPSK)
ITU-T V.23	1200 bps asymmetrical with 75 bps back channel with Frequency Shift Keying (FSK), used by some U.K. and European phone systems.
Bell 103	300 bps (ITU-T V.21 optional) asynchronous, Frequency Shift Keying (FSK)

Error Control, Data Compression, Testing, and Dialing

This modulation	Supports
ITU-T V.42	LAPM error control, 1200 bps and higher
MNP	Levels 2, 3 and 4 error control, level 5 data compression, 1200 bps and higher
HST	Asymmetrical mode, at 16.8/14.4/12 kbps; 9600/ 7200/4800 bps, 450/300 bps back channel
ITU-T V.42 bis	Data compression, 1200 bps and higher
ITU-T V.54	Digital and remote digital loopback testing
ITU-T V.25 bis	Dialing and answering method for automatic calling and/or answering equipment

Fax

Your Courier 56K Business Modem provides Group III -compatibility when controlled by Class 1 or Class 2.0 fax software. In addition, your Courier 56K Business Modem adheres to the following standards:

This modulation	Supports
TIA/EIA-578	Service Class 1 Asynchronous Facsimile DCE Control Standard
TIA/EIA-592	Service Class 2.0 Asynchronous Facsimile DCE Control Standard
ITU-T V.17	14.4/12 kbps
ITU-T V.29	9600/7200 bps
ITU-T V.27	ter 4800/2400 bps
ITU-T V.21	300 bps

Specifications

This feature	Supports
Supported serial port rates	230400, 115200, 57600, 38400, 19200, 9600, 4800, 2400, 1200, and 300 bps
Adaptive Speed Leveling (ASL)	21600, 19200, 16800, 14400, 12000, 9600, 7200, and 4800 bps
Serial port connector	DB-25
Communications channel	Full- or half- duplex on 2-wire phone lines; demand-driven high-speed turnaround in HST mode; symmestrical speeds in V.32 bis.
Data format	Binary, serial; defaults to 8-bit word length, no parity, and 1 stop bit.
	Word Length	Parity (1 Bit)	Stop Bits
	7	Even, odd, mark, space	1
	7	None	2
	8	None	1
Flow Control Buffers	Variable sizes
Command Buffer	56 characters, excluding the AT prefix, Carriage Return, and spaces
Test Options	Remote digital loopback, digital loopback, test pattern, and dial test
Failed Call Timeout	60 second default, programmable 2-255 sec.
Answer Tone Timeout	60 seconds
Answer Tone Detector	2080-2120 Hz
Loss of Carrier (Disconnect Timer)	0.7 second default, programmable 0.2-25.5 sec.
Equalization	Adaptive
Receive Sensitivity	- 43 dBm + 2 dBm
Transmit Level	- 9 dBm maximum
Transmitter Frequency Tolerance	.01%
Certification	FCC 15, EN55022 (CISPR 22), ICES-003, AS/NZS3548, VCCI; Class B; EN50082-1; UL/C-UL, IEC 950, EN60950, TS001; FCC 68, CTR 21
Ringer equivalence	0.4b

Serial Ports

Most computers provide a DB-25 or DB-9 port that conforms to the EIA-232 standard.

The EIA-232 Interface

Your modem’s serial port is factory set to signal according to the EIA-232 standard.

Wiring a DB-25 to DB-9 Cable

DB-9 connectors for PCs should be wired at the computer end of the cable as shown below.

Minimum Requirements

Some computer/terminal equipment supports only a few of your modem’s EIA-232 signals. The minimum required for your modem to operate asynchronously follows:

DB-25	DB-9	Supports this signal
Pin	Pin	Function
2	3	Transmitted Data
3	2	Received Data
7	5	Signal Ground
20	4	Data Terminal Ready

Flow Control Requirements

If your computer and software support Clear to Send and you wish to use Transmit Data hardware flow control (&H1), Pin 5 (DB-25) or Pin 8 (DB-9) is required.

If your computer and software support Request to Send and you wish to use Received Data hardware flow control (&R2), Pin 4 (DB-25) or Pin 7 (DB-9) is required.

Contents:

Appendixes