Westermo RM-455U-D - Manual (Page 28)

Chapter Three Configuration
Man_455U-D Rev 3.04 Page 29
Chapter Three CONFIGURATION
3.1 Before Configuring
Configuration comprises selecting parameter values for the operation of the 455U-D unit.
Before you start configuration, parameter settings must be decided. The main parameters
are:-
 Addressing - system address and unit address.
 Character type. You need to find out the character type of the host devices connected to
the 455U-D units. The most common character type is 8 data bits, no parity, 1 start bit
and 1 stop bit.
 Serial Data Rate. You need to find out the serial data rate used by the host devices. It is
possible to have different serial rates configured at different modules in the same system.
 Radio Data Rate. You need to decide what radio data rate you wish to use. It does not
have to be the same as the serial data rate. We recommend that you use 4800 bits/sec for
12.5KHz channel width or 9600 bits/sec for 25KHz channel - unless your application
requires the faster data rate to operate reliably. The radio range for the top data rate
(9600/19200 bits/sec) will not be as good as that for 4800/9600.
 Operating mode . You need to decide which operating mode you wish to use. Modes are
Unacknowledged or Acknowledged, error-checked or no-error-check.. These modes are
discussed in Chapter 1 and in more detail in following sections.
The other configuration parameters usually do not need to be changed, and are provided as a
means of "fine tuning" the operation of the 455U-D units.
Configuration may be achieved by three different methods:
1. Using a Windows configuration program run on a PC. This is the most common way of
configuring.
2. Using Hayes AT commands. This method can be performed manually by the user from a
PC terminal (for example, Hyperterminal), or can be performed automatically by the host
device.
3. Using the single DIP switch located in the end-plate of the module. This restores the
module to a factory default configuration which is suitable for a point-to-point
unacknowledged mode link.
3.1.1 Addressing
A 455U-D network comprises modules with the same “system” address. The system address
is a 16 bit value, 0 to 65 535 (two 16-bit registers, each with values 0 to 255). Only modules
with the same system address will communicate with each other. This feature allows more
than one system to operate in the same area on the same radio channel. If you are adding
another module to an existing system, use the same value as the existing modules. If you are
starting a new system, select random values and use the same value for each module.