CT_init(3) Functions to handle communication with integrated circuit cards and

Other Alias

CT_data, CT_close


#include <ctapi.h>

char CT_init(
unsigned short ctn,
unsigned short pn);

char CT_data(
unsigned short ctn,
unsigned char * dad,
unsigned char * sad,
unsigned short lenc,
unsigned char * command,
unsigned short * lenr,
unsigned char * response);

char CT_close(
unsigned short ctn);


This manual page describes the CT-API functions used to handle communication with integrated circuit cards and cardterminals. The CT-API functions are generic, and allows the use of memory cards (often referred as synchronous cards) and processor cards (often referred as asynchronous cards).

The CT-API implementation is dependent on the cardterminal that is used. For each cardterminal a CT-API library implementation should be provided, either by the manufacturer or by third parties. This manpage is not a complete specification of the CT-API, but a general overview of the most common functionalities.

CT_init() selects and initializes the interface with the cardterminal (f.i. serial port, USB bus, or any other type of connector). The CT_init() function must be called before communicating with the card or the cardterminal. A unique cardterminal number chosen by the caller is assigned by the CT-API library to the initialized connection.

Cardterminal number: identifies the connection with the cardterminal for further references. It's chosen by the caller of the function.
Port number: selects the physical interface. The port number assignment is dependent on the CT-API implementation. However most serial cardterminal implementations use the convention of assigning the value 0 to the first serial port, 1 to the second serial port and so on. See the file /usr/include/ctapi.h of your CT-API implementation for a list of allowed values.

CT_data() sends a command to the card or to the cardterminal and returns the response to the calling program.

Cardterminal number: the number specified in CT_init() call for this cardterminal.
Destination address. If the command is sent to the cardterminal, it must point to a variable containing the value CT (0x01). If the command is sent to a card, the destination address variable must be set to the number identifying the slot of the cardterminal where the card is inserted, ranging from ICC1 (0x00) and ICC2 (0x02) to ICC14 (0x0E).
On the return of the response, the variable pointed by dad is set to the value HOST (0x02) or REMOTE_HOST (0x05).
Source address. When the function is called it is usually set to point to a variable with the value HOST (0x02), although the value REMOTE_HOST (0x05) may ocurr in some applications if the CT-API implementation supports remote calls.
On the return of the response, the variable pointed by sad is set to any of the values from CT (0x01), ICC1 (0x00), ICC2 (0x02) to ICC14 (0x0E).
Command length in bytes.
Pointer to the buffer that conveys the command to be sent to the card or cardterminal.
Before function call, pointer to a variable containig the maximum buffer size in bytes for the response data. After successful function call it contains the size in bytes of the response data.
Pointer to the response data. Memory buffer of at least the size in bytes specified in lenr must be allocated before calling to the function.

CT_close() terminates the communication with the cardterminal which has been assigned to a logical cardterminal number by the function CT_init(). The function shall be called for each initialized cardtreminal before the end of the program in order to free resources if necessary.

Cardterminal number: as specified in CT_init() call for this cardterminal.


CT_init(), CT_data(), and CT_close() functions return a value of type char.

Function call was successful.
Invalid parameter or value.
Cardterminal Error. The cardterminal is temporarily not accessible (busy with other or internal processes). The problem can be solved by the application.
Transmission Error. Transmission errors due to mechanical, electrical or protocol failures. Reset of the cardterminal is necessary.
Memory assignment error. A memory error occurred (f.i. the allocated buffer is too small for the returned data).
Host Transport Service Interface error. Commonly returned if the error is produced by the software layer and not in the communication with the hardware.


This manual page was written by Carlos Prados <[email protected]>.