The function, pci_pad_chan writes an appropriate number of the current idle byte so that the number of bytes in the transmit buffer is both a multiple of 4 and represents a whole number of frames (based on the number of time slots used by the channel). This is necessary to ensure that all of the data written is transmitted before the transmit buffer underflows.

The pci_chan_forcexmt function sends a new command to the embedded code requesting that it transmit whatever data is currently in the transmit buffer. This circumvents the requirements for transmitting data that are normally used to avoid buffer underflow for streaming transmit channels: that either one second of data be in the transmit buffer or one second has elapsed since any new data has been written.

Both of these functions should be used following calls to pci_write_chan for channels sending bursty messages that are likely to underflow. For example:

      PCI_CHAN  *transmit;
      char      *message;
      int        msgsize;
      int        wrstat;

      /* Write new message, retry once in case of underflow */
      wrstat = pci_write_chan (transmit, message, msgsize);

      if (wrstat != msgsize && errno == EOVERFLOW)
         wrstat = pci_write_chan (transmit, message, msgsize);

      if (wrstat != msgsize)
          return -1;  /* return error condition */

      /* Add padding and force xmt after successful write */
      if (pci_pad_chan (transmit) < 0)
          return -1;  /* return error condition */

      if (pci_chan_forcexmt (transmit) < 0)
          return -1;  /* return error condition */

The pci_chan_forcexmt function requires version 1.4.1 of the DPT embedded code.

The pci_flush_chan function is fixed to include requesting the embedded code to force transmittion. However, this function does not return until the transmit buffer is empty which may impede writing new messages to the transmit buffer. It should only be used prior to closing a transmit channel to ensure that all data has been transmitted.

A new error code is added for when the pci_open_chan and pci_framer_set_mode functions fail because the board's port configuration is not compatible with the requested data direction. Previously these function would set errno to ENXIO when this error occurred. The new error code is PORT_CONFIG_ERROR which produces the following string returned by the _dpstrerror function:

"Port not configured for desired direction"

The pci_tdm_run function is fixed to update the hardware TDM map if it is not current.

The time-related functions in the cacipc library are now supported for Windows platforms.

The Linux device driver now includes header files to handle versioned symbols exported for kernel function calls. This resolves issues with unresolved symbol errors when attempting to load the device driver module.

The dpserial program's behavior is modified so that when no options are specified it will display the current EEROM settings and ask the user if they wish to edit the settings. A new -e option has the program enter the edit mode immediately.

A new program, dpheartbeat, demonstrates the handling of bursty transmission channels and measures transmit to receive latency.