User's Manual

Chapter 3 27
Using HDLC.FRAME Protocol
Status and Error Messages
E1/T1 interface
The following transmit completion status codes may be generated by the
HDLC.FRAME protocol on an E1/T1 interface.
Table 3-2 E1/T1 Interface Transmit Completion Status Codes
Transmit
Status Code
Description
IO_OK No error detected.
This message was successfully transmitted to the
receiving station.
IO_DSBL Terminal disabled.
Messages cannot be transmitted by a disabled terminal.
IO_DOWN Terminal down.
This message could not be sent because the physical
interface is not operational (usually when frame
synchronization has been lost).
IO_LONG_MSG There is a limit to the number of buffers which may be
used for a single transmit frame. If this limit is exceeded,
the frame is flushed with this status code, and is not
transmitted. Note: This ACC has a configurable buffer
size and a buffer size of 128 bytes or larger will prevent
this problem from occurring.
IO_TX_URUN Transmit underrun.
This frame could not be transmitted at this time due to
excessive loading of the interface card.