User`s guide

Creating a Serial Gateway
For applications of the SLTA hardware platform, which cannot use the LonTalk
network interface protocol on the EIA-232 link, the SLTA hardware may be
programmed for other data formats using Neuron C. For example, the SLTA
hardware may be used to connect ASCII devices such as printers, modems, and
terminals to a LONWORKS network. The SLTA hardware may also be
programmed to build a gateway between a foreign EIA-232-based protocol, such
as the serial port on a Programmable Logic Controller (PLC), and the LonTalk
protocol. The SLTA hardware without the firmware (e.g., without the PROM) is
called a programmable serial gateway.
The programmable serial gateway is used to create a LONWORKS application
node, so all the standard Neuron Chip firmware features described in the Neuron
C Programmer’s Guide are available to the application programmer. The
firmware images for NSI and MIP mode, as well as capabilities described in the
LONWORKS Host Application Programmer’s Guide are not available. For
example, there is no support for modem control or for more than 62 bound
network variables on such a node. The serial gateway will also not be usable as a
network interface for LonMaker, LonManager DDE Server, or LNS-based
applications, although it can still be installed and managed by such an
application.
SLTA / PSG History
Echelon manufactures (or has manufactured) the following LONWORKS serial
devices. Each device ships with firmware:
Product
SLTA
SLTAl2
Description
Original Serial LonTalk
Adapter
Second generation SLTA
Firmware
Firmware implemented MIP
level functionality
Status
Replaced by SLTA/2
Firmware implemented MIP
level functionality
Replaced by SLTA-10
SLTA-10
Third generation SLTA
Firmware implements MIP or
NSI level functionality
Current product
13-2
Programmable Serial Gateway