CAI 700 Multi-Point Sampler

Theta Engineering designed the electronics and created the firmware for this product used to sample up to 16 gas streams from various points in a processing plant for input to a CAI gas analyzer. An LCD TFT color touch screen was implemented as a local user interface. The design also supported controlling the system using MODBUS over the plant’s Ethernet network. The hardware was designed to be expandable allowing additional units (even devices not yet designed!) to be added in a daisy-chain fashion while retaining the same single point of control.

To make manufacturing and installation of the product as simple as possible, the firmware was designed to be self-configuring. No need to make a distinct version of the firmware for every possible hardware configuration; the firmware detects what hardware is present and configures itself automatically! The configuration percolates all the way up to the user interface. Screen controls for hardware functions not present will not be available.

To make things as easy as possible for operators and maintenance personnel, diagnostic indicators are provided to indicate faults such as open and shorted conditions on any wiring. These indicators can be seen on the screen as well as monitored using MODBUS.