Appendix
NOTE: Setting the interface module to Default Mode requires removing the cover of the module
to access the internal data converter.
Default Configuration
EEPROM in the interface module stores setup information and calibration constants and
replaces the usual array of switches and ports necessary for specification such as baud rate,
address, and parity. No batteries are used, which eliminates the need to open the kit.
EEPROM provides the ability to configure the module setup parameters remotely through the
communications port without having to physically change settings. Each module has an input
pin labeled DEFAULT*. By connecting this pin to Ground, the module is put in a known com-
munications setup called Default Mode.
The Default Mode settings are 9600 baud, one start bit, eight data bits, one stop bit, no parity.
Any address is recognized. The module answers to address "01" in Default Mode. Grounding
the DEFAULT* pin does not change any of the setups stored in EEPROM. The setup information
can be read back to determine all the setups stored in the module.
Put the module in Default Mode to change the setup information. The baud rate and parity
setups can be changed without affecting the Default Mode values of 9600 baud and no parity.
When the DEFAULT* pin is released, the module automatically performs an internal reset and
configures itself to the baud rate and parity stored in the setup information.
Use Default Mode only with a single module connected to a computer for the purpose of
identifying and modifying setup values. In most cases, a module in Default Mode cannot be
used in a string with other modules.
For simplicity, Watts recommends performing all the setups while in Default Mode. Put the module
in Default Mode by connecting the DEFAULT* terminal to the GND terminal using a jumper wire.
When the module is in Default Mode, the serial parameters are internally set to 9600 Baud, 8 data
bits, no parity, and one stop bit. The module responds to Modbus Slave address "01".
NOTE: No other wiring connections are required on the analog or digital I/O pins to perform
the module configuration.
Run the Utility Software
The Default* line being connected to the power supply ground is included within the wiring
connections. This connection places the module in Default Mode. Default Mode forces the
module into a known communications state and is best used for configuring the module. The
Default Mode serial communications parameters are 9600 baud, eight data bits, no parity,
and one stop bit. The module answers to Modbus Slave address "1" (0x01).
The module requires an application to change the setup register values. As the module communi-
cate through the Modbus RTU protocol, a Modbus Master program or the utility
software is required to change the module configuration.
The utility software is the best program to use when configuring the module. The utility software
reads the module information, displays the information in easy-to-understand terms, allows
changes to be made through drop-down menus, and then writes the new values to the module.
The module parameters can also be stored to disc and recalled later.
The utility software runs on Windows-based systems. Download the program from
https://www.watts.com/performance-monitoring then run Setup.exe. The utility installs and
creates a menu section named "DGH Data Acquisition." The utility software resides under
that selection.
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