Getting Started 1-3
settings. However, there is one minor drawback in using EEPROM instead
of switches; there is no visual indication of the setup information in the
module. It is impossible to tell just by looking at the module what the baud
rate, address, parity and other settings are. It is difficult to establish
communications with a module whose address and baud rate are unknown.
To overcome this, each module has an input pin labeled DEFAULT*. By
connecting this pin to Ground, the module is put in a known communications
setup called Default Mode.
The Default Mode setup is: 300 baud, one start bit, eight data bits, one
stop bit, no parity, any address is recognized.
Grounding the DEFAULT* pin does not change any of the setups stored in
EEPROM. The setup may be read back with the Read Setup (RS) command
to determine all of the setups stored in the module. In Default Mode, all
commands are available.
A module in Default Mode will respond to any address. A dummy address
must be included in every command for proper responses. The ASCII value
of the module address may be read back with the RS command. An easy
way to determine the address character is to deliberately generate an error
message. The error message outputs the module’s address directly after
the “?” prompt.
Setup information in a module may be changed at will with the SetUp (SU)
command. Baud rate and parity setups may be changed without affecting
the Default values of 300 baud and no parity. When the DEFAULT* pin is
released, the module automatically performs a program reset and config-
ures itself to the baud rate and parity stored in the setup information.
The Default Mode is intended to be used with a single module connected to
a terminal or computer for the purpose of identifying and modifying setup
values. In most cases, a module in Default Mode may not be used in a string
with other modules.
RS-232 & RS-485 Quick Hook-Up
Software is not required to begin using your D3000/4000 module. We
recommend that you begin to get familiar with the module by setting it up on
the bench. Start by using a dumb terminal or a computer that acts like a dumb
terminal. Make the connections shown in the quick hook-up drawings,
Figures 1.1 or 1.2. Put the module in the Default Mode by grounding the
DEFAULT* terminal. Initialize the terminal communications package on
your computer to put it into the “terminal” mode. Since this step varies from
computer to computer, refer to your computer manual for instructions.
Connect a suitable voltmeter or ammeter to the output connections of the
module to monitor the output signal. If an ammeter is not available to
