Selecting 'Detailed AT Commands' in the KlasDrive setup box instructs KlasDrive to display all CAPI messages and AT commands it sends and receives. The messages, displayed in the KlasDrive main window, come in four different varieties, each documenting a different event.

1. AT commands written by the comms application to the virtual COM port. These messages are displayed by KlasDrive as text, if they are readable, or as hexadecimal otherwise. They are prefixed by the identifier: AT Write Data
   eg: AT Write Data : ATD00441212759113 0D
    
2. AT commands echoed back to the comms application by KlasDrive.
   eg: AT Read Data : ATD00441212759113 0D
    
3. CAPI messages sent or received by KlasDrive. The CAPI message type and the message parameters are displayed in detail. The first line of each message describes the message type, length, application ID (identifies this application instance with CAPI), message type code, and sequential message number. CAPI messages take the form of Request and Confirmation (or Indicator and Response) pairs, where Requests are messages sent to CAPI and Indicators are messages sent by CAPI. For example:
   
   CONNECT_REQ : Length : 0033 AppId : 0001 Command : 0280 Message : 0002
   Controller : 00000001
   CIP Value : 0002
   Called Number Length : 0F
   Called Number BChannel : 80
   Called Number : 00441212759113
   B Protocol Length : 09
   B1 Protocol : 0000
   B2 Protocol : 0001
   B3 Protocol : 0000
   Add Info Length : 04
   
   This example illustrates a CAPI CONNECT_REQ message sent by KlasDrive to the CAPI driver. In the example below it is immediately followed by a CAPI CONNECT_CONF message.
    
4. Other significant and informational messages are displayed by KlasDrive during a session. Examples of these are
   CAPI 2.0 Windows driver successfully loaded
   Dialling 00441212759113...

These messages can be used to trace the progress of incoming or outgoing calls and can give you an indication of where problems may lie.

This section illustrates a sample session with KlasDrive. In this example an Internet Application starts a Winsock which dials a commercial ISP at the number 00-44-121-2759113. KlasDrive dials this number and sends back a connect message to indicate that it was successful, and data transfer begins. The CAPI messages can be seen to correspond to the standard CAPI dialing sequence as illustrated elsewhere.

CAPI Signal
AppId : 0001

CAPI Release
AppId : 0001

CAPI Register
Queue Buffer Size : 2048
Connections : 1
Receive Blocks : 7
Send Blocks : 4
Block Length : 2048
AppId : 0001

CAPI Signal
AppId : 0001

LISTEN_REQ : Length : 001A AppId : 0001 Command : 0580 Message : 0001
Controller : 00000001
Info Mask : 00000000
CIP Mask : 0000000C
CIP Mask2 : 00000000
Calling Number Length : 00
Calling Subaddress Length : 00

CAPI 2.0 Windows driver successfully loaded

LISTEN_CONF : Length : 000E AppId : 0001 Command : 0581 Message : 0001
Controller : 00000001
Info : 0000

AT Write Data : ATD00441212759113 0D

Dialling 00441212759113...

CONNECT_REQ : Length : 0033 AppId : 0001 Command : 0280 Message : 0002
Controller : 00000001
CIP Value : 0002
Called Number Length : 0F
Called Number BChannel : 80
Called Number : 00441212759113
B Protocol Length : 09
B1 Protocol : 0000
B2 Protocol : 0001
B3 Protocol : 0000
Add Info Length : 04

CONNECT_CONF : Length : 000E AppId : 0001 Command : 0281 Message : 0002
PLCI : 00000101
Info : 0000

AT Read Data : ATD00441212759113 0D

CONNECT_ACTIVE_IND : Length : 000F AppId : 0001 Command : 0382 Message : 00BF
PLCI : 00000101

CONNECT_ACTIVE_RESP : Length : 000C AppId : 0001 Command : 0383 Message : 00BF
PLCI : 00000101

CONNECT_B3_REQ : Length : 000D AppId : 0001 Command : 8280 Message : 0003
PLCI : 00000101
NCPI :  00

CONNECT_B3_CONF : Length : 000E AppId : 0001 Command : 8281 Message : 0003
NCCI : 00010101
Info : 0000

CONNECT_B3_ACTIVE_IND : Length : 000D AppId : 0001 Command : 8382 Message : 00C0
NCCI : 00010101
NCPI :  00

CONNECT_B3_ACTIVE_RESP : Length : 000C AppId : 0001 Command : 8383 Message : 00C0
NCCI : 00010101

DATA_B3_REQ : Length : 0016 AppId : 0001 Command : 8680 Message : 0004
NCCI : 00010101
Pointer : 18E70000
Data Length : 0018
Data Handle : 0000
Flags : 0000
Data :  FF 03 C0 21 01 02 00 14 02 06 00 00 00 00 05 06 00 0E 61 3D 07 02 08 02

DATA_B3_CONF : Length : 0010 AppId : 0001 Command : 8681 Message : 0004
NCCI : 00010101
Data Handle : 0000
Info : 0000

DATA_B3_IND : Length : 0016 AppId : 0001 Command : 8682 Message : 00C1
NCCI : 00010101
Pointer : 192F0800
Data Length : 0021
Data Handle : 0000
Flags : 0000
Data :  FF 03 C0 21 01 01 00 1D 00 04 00 00 01 04 05 F4 03 04 C0 23 11 04 05 F4 13 09 03 00 C0 7B...

DATA_B3_RESP : Length : 000E AppId : 0001 Command : 8683 Message : 00C1
NCCI : 00010101
Data Handle : 0000

Data transfer continues....