cc_SetChanState( )

Description | Termination Events | Cautions | Example | Errors | See Also

Name:	int cc_SetChanState(linedev, chanstate, mode)
Inputs:	LINEDEV linedev	line device handle
	int chanstate	channel service state
	unsigned long mode	synchronous or asynchronous
Returns:	0 on success < 0 on failure
Includes:	cclib.h
Category:	System tools
Mode:	synchronous or asynchronous
Technology:	PRI (all protocols)

Description

The cc_SetChanState( ) function is used to change the maintenance state of a specified B channel. When power is first turned on, all channels are placed in the IN_SERVICE state. However, in some protocols, the D channel may need to be activated.

NOTE:

This feature may not be available in some countries.

Parameter	Description
linedev:	The line device handle of the B channel.
chanstate:	The channel service state. Possible values for chanstate are:   IN_SERVICE - Informs the board that the host is ready to receive and send a message.   MAINTENANCE - Informs the host that normal outgoing traffic is not allowed. Only an incoming test call is permitted.   OUT_OF_SERVICE - Informs the board that the host is not ready to receive or send a message. For some protocols, the firmware will reject all incoming and outgoing requests.
mode:	Specifies asynchronous (EV_ASYNC) or synchronous (EV_SYNC) mode.

Termination Events

• CCEV_SETCHANSTATE - indicates that the B channel has been placed in the requested state.
• CCEV_TASKFAIL - indicates that a request/message was rejected by the firmware. Typically, this event is triggered by an incorrect function call during the call.

Cautions

• The cc_SetChanState( ) function should only be invoked in the Null state. The Null state occurs immediately after a call to either the cc_Open( ) or cc_ReleaseCall( ) function.
• The cc_SetChanState( ) function affects only the link between the calling process and the device. Other processes and devices are not affected.
• cc_SetChanState( ) is not supported for E-1 ISDN or NTT PRI protocols, or for any BRI protocols.

Example

#include <windows.h>   /* For Windows applications only */  
#include <stdio.h>  
#include <errno.h>  
#include "srllib.h"  
#include "dtilib.h"  
#include "cclib.h"  
void main()  
{  
   LINEDEV   devhdl    = 0;  
   CRN       crn = 0;  
   char     *devname = "dtiB1T1";  
   if ( cc_Open(&devhdl, devname, 0) < 0 )   
   {  
      printf("Error opening device: errno = %d\n", errno);  
      exit(1);  
   }  
        /*   
         * using cc_SetChanState(devhdl, IN_SERVICE,   
         * EV_SYNC) to set B channel to "in service" state.  
         * Recommended for all supported protocols.  
         */   
   if ( cc_SetChanState(devhdl, IN_SERVICE, EV_SYNC) < 0 )   
        procdevfail(devhdl);  
   if ( cc_WaitCall(devhdl, &crn, NULL, -1, EV_SYNC) < 0 )  
        procdevfail(devhdl);  
   if ( cc_AnswerCall(crn, 0, EV_SYNC) < 0 )  
        callfail(crn);  
        .  
        .  
        .  
        .  
        .  
   /* Drop the call */  
   if ( cc_DropCall(crn, NORMAL_CLEARING, EV_SYNC) < 0 )  
        callfail(crn);  
   if ( cc_ReleaseCall(crn) < 0 )  
        callfail(crn);  
   /* Close the device */  
   if ( cc_Close( devhdl ) < 0 )   
      printf("Error closing device, errno = %d\n", errno);  
}  
int callfail(CRN crn)  
{                 
        LINEDEV ld;  
         cc_CRN2LineDev(crn,&ld);  
         procdevfail(ld);  
}  
int procdevfail(LINEDEV handle)  
{  
        int reason;  
        char *msg;  
        reason = cc_CauseValue(handle);  
        cc_ResultMsg(handle, reason, &msg);  
        printf("reason = %x - %s\n",reason,msg);  
}

Errors

If the function returns < 0 to indicate failure, use the cc_CauseValue( ) function to retrieve the reason code for the failure. The cc_ResultMsg( ) function can be used to interpret the reason code. Error codes are defined in the files ccerr.h, isdnerr.h, and isdncmd.h.

Error codes from the cc_SetChanState( ) function include the following:

Error Code	Description
ERR_ISDN_LIB | E_ISBADTS	Bad time slot
ERR_ISDN_LIB | E_ISBADIF	Bad interface number
ERR_ISDN_LIB | E_ISBADPAR	Bad input parameter

See Also

• cc_WaitCall( )

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