Echelon LonTal Stack - Manual (Page 140)

128 Developing a LonTalk Stack Device Application
To return a LonTalk Stack device to the legacy mode, rather than the extended
mode, perform one of the following tasks:
• Re-run the LonTalk Interface Developer utility to generate a new
signature for the device, and rebuild and load the application image.
• Send the NM_NODE::NM_INITIALIZE extended network management
command to the device.
• Erase the non-volatile memory for the device.
• If the device is currently commissioned in an OpenLNS database,
de-commission it.
You should not need to perform any of these tasks often because most network
management tools use OpenLNS or are compatible with ECS.
For more information about the LonTalk extended command set (ECS) network
management commands, see the ISO/IEC 14908-1 Control Network Protocol
Specification. This document is available from ISO:
www.iso.org/iso/home/store/catalogue_tc/catalogue_detail.htm?csnumber=60203
Using Direct Memory Files
To use configuration properties in files, your host application program must
implement a method that allows the network management tool to access those
files. You can support either one of the following:
• The L ON W ORKS FTP protocol
• The host direct memory files (DMF) feature
The FTP protocol is appropriate when large amounts of data need to be
transferred between the host processor and Echelon Smart Transceiver or
Neuron Chip. The host DMF feature is appropriate for most other cases.
By supporting direct memory files, your application allows the network
management tool to use standard memory read and write network messages to
access configuration property files located on the host. Direct memory files
appear to the network management tool as if they were located within the
Echelon Smart Transceiver or Neuron Chip’s native address space, but the
LonTalk host stack routes memory read and write requests within the DMF
memory window to the LonMemoryRead() and LonMemoryWrite() callback
handler functions provided in the FtxlHandlers.c file. These functions use the
LonTranslateWindowArea() support function, which is generated by the
LonTalk Interface Developer utility to translate between Echelon Smart
Transceiver or Neuron Chip addresses and host addresses.
If the model file contains a network variable of type SNVT_address, the
LonTalk Interface Developer utility automatically generates all necessary code
and data for the memory read and write requests, including code in the
LonInit() function to register the virtual memory window with the LonTalk Host
stack.
You do not generally need to modify the code that the LonTalk Interface
Developer utility generates (in FtxlDev.c) or the LonMemoryRead() and
LonMemoryWrite() callback handler functions (in FtxlHandlers.c).