AC500-eCo/S500-eCo: Short Description HardwareΒΆ

Processor Modules

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AC500-eCo Processor Modules contains the CPU with the core microprocessor of the PLC. It is integrated with power supply, input channel and communication interface.

  • To download user programs
  • To run the CPU
  • To execute user programs in loops
  • To monitor program input and output devices.

Processor Modules are available in different performance classes and provide different amounts onboard I/Os.

Only one Processor Module is required for a valid system architecture.

If required, Processor Modules are also available with ETHERNET interface.

I/O Modules

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If the amount of onboard I/Os provided on the Processor Module is insufficient for a certain use case, the PLC can be expanded with I/O Modules to meet the control requirements.

Memory

In the PLC, the memory is mainly used for saving system programs, user programs and work data. The following memory types can be distinguished:

  • Volatile memory:

    All saved data will be lost after power failure of the memory but the memory can provide high access rate and unlimited programming cycles. Common volatile memories mainly include SRAM and DRAM (including common memories such as SDRAM).

  • Nonvolatile memory:

    All saved data will not be lost after power failure of the memory, but the memory is subject to low read-write rate and limited rewrite cycles. Common nonvolatile memories mainly include NORflash, NANDflash, EEPROM, SD card, etc.

AC500 PLCs store all user programs in the nonvolatile memory to get protected from power failure. The programs are exported to the volatile memory under operation of the PLC to ensure high-speed and efficient operation. If user program debugging is finished, the programs can be fixed in the nonvolatile memory when they need no change. The work data is subject to frequent change and access in the PLC operation. It is saved in the volatile memory to meet the requirements for random access.

The work data memory of PLC has the memory area for input and output relay, auxiliary relay, timer, counter and other logic devices. The state of these devices depends on initial setting and operation of the user programs. Some data maintains existing state by using built-in supercapacitors or backup batteries in case of power failure. The memory area for data saving in case of power failure is called the data retention area.

Power Supply

The CPU is equipped with a switch power supply for internal circuit. Compared with ordinary power supply, the PLC power supply has the higher stability and interference immunity. A number of PLC products provide DC 24V stabilized voltage supply to meet external sensors.