# CMM III

URL: https://irs.systems/en/docs/cmm-iii

The current measurement module CMM_III can be used to measure, evaluate and check current consumption of a dynamic DC load, typically an automotive electronic control unit. It can measure currents from 1µA to 100A<sub>DC</sub> (190A range) with automatic range selection within a few microseconds. The current range from 1µA to 190A is split into 7 Ranges, i.e., seven decades.



## Purpose of this document

Purpose of this document is to describe how to integrate the module in a test system and how to access it from the software point of view. Limits of application are shown in the [technical data](/en/docs/cmm-iii/hardware#technical-data) section.

This document is addressed to system integrators and the users, who are applying the module.

## Definitions and abbreviations

| Abbreviation | Definition |
| --- | --- |
| CMM | Current Measurement Module |
| CAN | Controller Area Network (network for output data) |
| LVDS | Low Voltage Differential Signaling (used as signal level for SPI) |
| SPI | Serial Peripheral Interface (clock synchronous data output) |
| DUT | Device Under Test (Device, whose current should be monitored) |

## References

| Document | Date | Description |
| --- | --- | --- |
| Datasheet SN65HVD230 | Feb 2011 | |
| Datasheet DS90LV049 | April 2013 | |

## Document Overview

This document contains 3 sections.

- The first section includes an introduction to this manual.
- The second section includes description of the hardware.
- The third section includes accessing the module from the software point of view.