FET1052-C System on Module Applied in FTU

FTU Features:

  • 1. AC collection: collect trivolt alternative current voltage and current(3U3I);
  • 2. Metering and counting of voltage, current, zero-sequence current, active power, reactive power, power factor and frequency;
  • 3. DC collection, 2-channel DC input;
  • 4. Status collection: power switch status, grounding switch status; 
  • 5. 113 times calculation of harmonic components and trivolt and unbalance factor counting; 
  • 6.remote signal input(passive, 24V) and remote control output(switch on or off, normally open);
  • 7. sequence of event, historical data, local storage of distributed information from host station;
  • 8. can support IEC 608705101,IEC 608705104,CDT92,DNP3.0,MODBUS protocols; 
  • 9. multiple communication solution: 2x RS232 or 2x RS485,  2x 10M/ 100M Ethernet
  • 10. can support GPRS;
  • 11. fault detecting and analysing: over-current, over-load;
  • 12. with backup power to prevent insufficient main power supplying; 
  • 13. can support NTP; 

FTU on market are mostly in structure of MCU combines with MPU, here we will introduce a solution which can realise the solution just on one MCU.

Here is a toplogical of the solution:

By this solution, we can do development work about encryption, file system and communication protocols based on Linux system, and the MCU will process real time tasks and remote control management. But

the disadvantage is that this solution may increas cost.

FET1052-C system on module is based on NXP Cortex-M7 featuring i.MX RT1052 processor with frequency up to 528MHz, SRAM 512 KB(TCM), SDRAM 16MB(32MB optional), QSPI-Nor Flash 4MB(16MB optional).

FTU hardware solution based on FET1052-C

  1. 1. 16-bit ADC chipset AD7607-8 from ADI company, can be expanded by SPI, it's used for trivolt current and voltage detection, can support 8 sampling channels, each channel sampling rate up to 200Ksps, built-in voltage reference, can support real ±10V and ±5V signal input. 2x ADC for DC detection, current detection will use differential AD input to improve accuracy;
  2. 2. 15-16 GPIO, for remote signal input and remote output, also status mornitoring and LED playing;
  3. 3. ARM Cortex-M7 processor frequency up to 528MHz, can support single accuracy and dual accuracy floating unit FPU for harmonic calculation;
  4. 4. 4x UART, 2 are used as RS232 and 2 are used as RS485, one UART can be used for GPRS or 4G, and one can be used for line loss module;
  5. 5. 2x Ethernet, one circuited to external PHY chipset KZ8081, and the other one circuited to external Ethernet controller W7500(contains TCP/ IP,embedded transformer and RJ45) by UART, and with buit-in 48-bit unique MAC;
  6. 6. 1x IIC, for RTC chipset RX8010SJ, the native RTC power consumption is as high as mA, while external RTC chipset power consumption is as low as nA, which can help prolonging battery life cycle;
  7. 7. FET1052-C has on-board 16MB SDRAM and 4MB的QSPI NorFlash can be used for program and data storage;
  8. 8. 1x SPI for ESAM chip;
  9. 9. CPU has 2x CAN2.0B controllers, transfering rate up to 1MB/s;
  10. 10. temperature detection by DS18B20 compliants with GPIO monobus protocol;
  11. 11. CPU has built-in watchdog timer, can support 0.5-128 seconds time-out setting.

FTU Software Solution:

❶ development based on Linux system

■ advantage: make development easier especially in network protocols(TCP/ IP, UDP, FTP, Telnet, SNTP) and file system(EXT3, EXT4, FAT32)

■ disadvantage: it is not a real time system which may cause interruption latency longer. Also Linux sysem is generally based on CPU with MMU which may increase cost;

❷ development based on FreeRTOS

▼ driver source: