MODEMDEVCAPS structure (mcx.h)

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Contains information about the capabilities of a modem.

Syntax

typedef struct _MODEMDEVCAPS {
  DWORD dwActualSize;
  DWORD dwRequiredSize;
  DWORD dwDevSpecificOffset;
  DWORD dwDevSpecificSize;
  DWORD dwModemProviderVersion;
  DWORD dwModemManufacturerOffset;
  DWORD dwModemManufacturerSize;
  DWORD dwModemModelOffset;
  DWORD dwModemModelSize;
  DWORD dwModemVersionOffset;
  DWORD dwModemVersionSize;
  DWORD dwDialOptions;
  DWORD dwCallSetupFailTimer;
  DWORD dwInactivityTimeout;
  DWORD dwSpeakerVolume;
  DWORD dwSpeakerMode;
  DWORD dwModemOptions;
  DWORD dwMaxDTERate;
  DWORD dwMaxDCERate;
  BYTE  abVariablePortion[1];
} MODEMDEVCAPS, *PMODEMDEVCAPS, *LPMODEMDEVCAPS;

Members

dwActualSize

The size of the data actually returned to the application, in bytes. This member may be less than the dwRequiredSize member, if an application did not allocate enough space for the variable-length portion of the structure.

dwRequiredSize

The number of bytes required for the entire MODEMDEVCAPS structure, including the variable-length portion.

dwDevSpecificOffset

The offset of the provider-defined portion of the structure, in bytes relative to the beginning of the structure.

dwDevSpecificSize

The size of the provider-defined portion of the structure, in bytes.

dwModemProviderVersion

The version of the service provider. The format and use of this member depends on the service provider.

dwModemManufacturerOffset

The offset of a text string that contains the name of the modem manufacturer, in bytes relative to the beginning of the structure.

dwModemManufacturerSize

The length of the modem manufacturer name, in bytes. The string is not null-terminated.

dwModemModelOffset

The offset of a text string that contains the model of the modem, in bytes relative to the beginning of the structure.

dwModemModelSize

The length of the model name, in bytes. The string is not null-terminated.

dwModemVersionOffset

The offset of a text string that gives the version and revision of the attached modem, if the provider could determine the information. The offset is specified in bytes relative to the beginning of the structure.

dwModemVersionSize

The length of the modem version string, in bytes. The string is not null-terminated.

dwDialOptions

The dialing options supported by the modem device. This member can be zero or more of the following values.

Value Meaning
DIALOPTION_BILLING
0x00000040
 The modem supports waiting for billing tone (bong).
DIALOPTION_DIALTONE
0x00000100
 The modem supports waiting for a dial tone.
DIALOPTION_QUIET
0x00000080
 The modem supports waiting for quiet.

dwCallSetupFailTimer

The maximum call setup timeout supported by the modem, in seconds. This is the largest value that can be specified for the corresponding member of the MODEMSETTINGS structure.

dwInactivityTimeout

The maximum inactivity timeout supported by the modem, in tenths of seconds. This is the largest value that can be specified for the corresponding member of the MODEMSETTINGS structure.

dwSpeakerVolume

The speaker volume settings supported by the modem. This member can be zero or more of the following values.

Value Meaning
MDMVOLFLAG_HIGH
0x00000004
 The modem supports high (MDMVOL_HIGH) volume.
MDMVOLFLAG_LOW
0x00000001
 The modem supports low (MDMVOL_LOW) volume.
MDMVOLFLAG_MEDIUM
0x00000002
 The modem supports medium (MDMVOL_MEDIUM) volume.

dwSpeakerMode

The speaker mode settings supported by the modem. This member can be zero or more of the following values.

Value Meaning
MDMSPKRFLAG_CALLSETUP
0x00000008
 The modem supports the MDMSPKR_CALLSETUP speaker mode.
MDMSPKRFLAG_DIAL
0x00000002
 The modem supports the MDMSPKR_DIAL speaker mode.
MDMSPKRFLAG_OFF
0x00000001
 The modem supports the MDMSPKR_OFF speaker mode.
MDMSPKRFLAG_ON
0x00000004
 The modem supports the MDMSPKR_ON speaker mode.

dwModemOptions

The modem options. This member can be zero or more of the following values.

MDM_BLIND_DIAL (0x00000200)

MDM_CCITT_OVERRIDE (0x00000040)

MDM_CELLULAR (0x00000008)

MDM_COMPRESSION (0x00000001)

MDM_DIAGNOSTICS (0x000000800)

MDM_ERROR_CONTROL (0x00000002)

MDM_FLOWCONTROL_HARD (0x00000010)

MDM_FLOWCONTROL_SOFT (0x00000020)

MDM_FORCED_EC (0x00000004)

MDM_SPEED_ADJUST (0x00000080)

MDM_TONE_DIAL (0x00000100)

MDM_V23_OVERRIDE (0x00000400)

When MODEMDEVCAPS is used to set modem options, as part of the MODEMSETTINGS structure, these values are used as follows.

Value Meaning
MDM_CCITT_OVERRIDE
0x00000040
 When set, CCITT modulations are enabled for V.21 and V.22 or V.23.

When clear, bell modulations are enabled for 103 and 212A.
MDM_V23_OVERRIDE
0x00000400
 When set, CCITT modulations are enabled for V.23.

When clear, CCITT modulations are enabled for V.21 and V.22.
 

For V.23 to be set, both MDM_CCITT_OVERRIDE and MDM_V23_OVERRIDE must be set.

dwMaxDTERate

The maximum DTE rate in bits per second.

dwMaxDCERate

The maximum DCE rate in bits per second.

abVariablePortion[1]

Variable-length information, including strings and any provider-defined information.

Requirements

Requirement Value
Minimum supported client Windows XP
Minimum supported server Windows Server 2003
Header mcx.h (include Windows.h)

See also

MODEMSETTINGS