Memory Consumption

Input and output memory specification:

Scope

Type

Maximum Value per Task*

M580 CPU

input bytes per device

up to 32,768, depending on CPU model

output bytes per device

up to 24,576, depending on CPU model

Ethernet RIO

input words per drop

1400

output words per drop

1400

Ethernet DIO

input bytes per device

up to 1,400, depending on EtherNet/IP or Modbus/Modbus function code.

output bytes per device

1,400

Total DIO scanning capability

input Kbytes

up to 4, depending on CPU model

output Kbytes

up to 4, depending on CPU model

* You can use all four tasks (MAST, FAST, AUX0, AUX1) simultaneously.

Displaying I/O Memory Consumption

You can monitor the I/O memory consumption in Control Expert . Use one of these methods:

  • In the Project Browser , expand Project > Configuration > EIO Bus . Right-click Properties .

    — or —

  • In the background of the EIO Bus window, right-click Bus properties .

    — or —

  • In the Edit menu, select Bus properties .

Exceeding RIO Drop Limitations

Control Expert displays an error in the log window if one of these events occurs:

  • The size of the RIO drop memory for the MAST task exceeds 1,400 input bytes or 1,400 output bytes.

  • The size of the RIO drop memory for the FAST task exceeds 1,400 input bytes or 1,400 output bytes.

  • The size of the RIO drop memory for the AUX0 task exceeds 1,400 input bytes or 1,400 output bytes.

  • The size of the RIO drop memory for the AUX1 task exceeds 1,400 input bytes or 1,400 output bytes.

  • The size of the M580 network exceeds 80% of the maximum drop limitation for the CPU chosen.

Minimum / Maximum System Channels

The minimum and maximum number of channels that an M580 configuration can manage is a function of the Modicon M580 CPU model that you are using. For detailed information on configuring channels, refer to the M580 Hardware Reference Manual.