Page C-2
LiQuilaz II E and S Operations Manual
Appendix C Modbus TCP Protocol
The map delineates three types of register assemblies:
1 Unary
: an individual register
2 Dual
: a register pair used for a 32 bit representation
3 String
: a group of registers containing ASCII bytes
There is a setting available that toggles the interpretation of selected dual-register
values. These values can be interpreted as integer representations of floating point
numbers with a fixed scaling factor or as IEEE-754 floating point representations of that
value. Refer to the register map to determine which register pairs have this feature
applied. This setting can be made in the setup interface, and saved in non-volatile
storage, or set real-time via the associated coil.
Even though the Modbus protocol itself is standard, the contents of the registers are
application-specific. A description of the register map is the definitive specification for
that application interface. The following Modbus register map has comments and
notes to help with its intended use.
Input Registers
The input registers are in two sections:
Configuration
and
Data
.
The
Configuration
section description begins on this page.
The
Data
section description begins on page
Configuration Section
The
Configuration
section contains:
• Modbus Map Version
• Sensor Firmware Version
• Product Name
• Flow Rate and Volume Scale Factors
• Flow Rate
• Number of Channels (Particle & Analog)
• Particle Channel sizes
