This section covers what is meter tampering, why is this a problem for utility providers, and some common ways a meter is tampered.
The first line of defense against tampering by bypassing current, reversing connections, and disconnecting leads is the meter case. Due to this, it is common for utilities to require some form of intrusion detection system to detect when someone opens a case. In this section, we will cover how to detect someone trying to open the case of a meter.
For anti-tampering, it is common to try to detect the presence of a strong magnet. In this section, we will cover the use of hall sensors for low-power detection of strong magnetic fields in three dimensions. Details on our magnetic tamper detection reference design, TIDA-00839, will be provided as well as some of the design considerations that were kept in mind when creating this reference design.
In this section, we will cover how to harden a meter against these magnetic tamper attacks by using shunts for current sensors. For poly-phase implementations, I will go over how to use isolated delta sigma modulators to add the necessary isolation to use shunt current sensors and create magnetically immune poly-phase energy measurement systems. The TIDA-00601 and TIDA-01094 reference designs, which show how to implement a poly-phase isolated shunt measurement system, will be discussed as well as the associated AMC1304 high-side power supplies used in these designs.
In this section, a summary of the entire “Anti-tamper Techniques to Thwart Attacks on Smart Meters” training module would be covered. This summary would cover the “Detecting case tamper attacks using inductive switches “, “Detecting magnetic tampering using hall-effect sensors “, and “Hardening a meter against magnetic tamper attacks “ sections of the training series. Links will be provided for the reference designs and design tools that were discussed during this training series.
The TMP116 digital precision temperature sensor for the -55 to +125ºC range achieves higher accuracy than the Class AA PT sensor with a 1-point calibration. A small PCB including TI's TPD1E10B06 or TPD1E04U04 protection devices can be sealed into a RTD metal tube and meet the EN 61000-4-2 and -4-4 levels of ESD protection. The 64-bit internal EEPROM inside TMP116 stores user defined calibration data into the digital temperature sensor, simplifying integration with application MCUs, such as MSP430FR6047, FR6989 or CC13xx/26xx wireless MCU families.