Using HDLC/LAP-D Protocol

Status and Error Messages

Status and Error Messages

HDLC/LAP-D produces a range of buffer status codes and unsolicited status messages, apart from the standard communications statuses described elsewhere in the ACC documentation. In the following descriptions, the statuses marked with a dagger (†) are not generated by UI terminals. The defines for these status codes are located in /usr/include/zcom/zcomstatus.h and /usr/include/zcom/zx25status.h.

Terminal Request Status Codes

The following statuses are returned in response to a request to create, destroy, enable, disable, activate or deactivate a terminal. Although these are a part of the standard status set, they are not used by all protocols, and have a particular significance within HDLC/LAP-D.

0

TM_OK

No error detected

 

 

The request was successfully processed. In the case of

 

 

enabling or disabling the terminal, this does not mean

 

 

that the link has been established or disconnected. The

 

 

link status is reported via unsolicited status messages.

1

TM_MUST_DSBL

Terminal must be disabled

 

 

This status code is returned in response to a terminal

 

 

delete request. Before deleting a terminal, it must be

 

 

disabled and the ST25DSBL unsolicited status message

 

 

must have been received.

12

TM_PROT_REJ

Protocol detected error

 

 

TM_PROT_REJ is returned in response to a terminal

 

 

enable request when the configuration specified by the

 

 

poll, select and option words is invalid. In addition to

returning TM_PROT_REJ, the protocol generates a ST25ENF unsolicited status message. For configuration information, Chapter 4 , “Protocol Specific Configuration.” Another possible, although unlikely, cause for TM_PROT_REJ is that an error occurred when the protocol attempted to setup a group of LAP-D terminals. In this case, the ST25ENF unsolicited status message will not be generated.

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Chapter 3