C1b#
Description#
The isolated controller consists of two parts: The C1b which is the controller module situated in the left-most slot of the SPI rack chassis, and the C2 SPI isolator control box. The connection between the PC and SPI goes via the C1b in order to prevent unwanted ground loops or ground connections. The isolated controller is therefore ideal when for DC measurements.
![A C1b controller module.](../../_images/FrontC1b.png)
C1b#
The C1b module does not contain any clocked logic, apart from when data is being written. The main function of the C1b module is to direct the incoming data from the PC via the C2 isolator box, to the correct module via the backplane. The C1b also contains temperature sensor and a two channel ADC to measure the raw battery voltage. The ADC can be used by the user to monitor the batteries, to see when they need replacement or to mointor if the gyrator is still functioning.
Above is the block diagram of the connection between the C1b controller module and the PC.
C2#
The C2 isolator box contains an ARM microcontroller which interprets the incoming USB data from the PC. Then, the microcontroller transmits the signal as SPI data to the C1b inside the SPI rack via a displayport cable. The signal passes through a PCB which galvanically isolates the signal.