Schneider Electric 840 USE 106 0 manual Customizing Options, Custom State, Area

Theory of 984 HSBY Operation

Customizing Options

Custom State	If you want to set up a custom state RAM transfer area, you can control your
RAM Transfer	transferred amounts using a Hot Standby configuration extension (refer to Additional
Area	Guidelines for IEC Hot Standby , p. 147). The configuration extension provides three
	alternatives to the default transfer area:

You can define the number of 0x, 1x, 3x, and 4x reference data types that you want transferred in each scan.

You can define a certain amount of reference data types to be transferred on each scan with additional data to be transferred in groups over multiple scans,

lbeginning with 0x registers and proceeding in turn with 1x, 3x, and 4x registers. You can transfer all the configured reference data types in your system’s state RAM on every scan.

These options allow you to design a transfer area that is as small as 16 4x output registers or large enough to encompass all of your controllers’ state RAM (10K, 32K, or 64K, depending on the type of Quantum controllers you are using in your Hot Standby system).

The reference data of each type (0x, 1x, 3x, and 4x) is placed in the state RAM transfer area, starting at the lowest reference number (000001 for coils, 100001 for discrete inputs, 300001 for register inputs, and 400001 for register outputs). It is accumulated contiguously up to the amount of each data type you specify. The total number of each reference type in the state RAM transfer area must be a multiple of 16.

For example, if you indicate that the number of coils in the transfer area is 96, coils 000001... 000096 are transferred from the Primary to the Standby controller. Any 0x references beyond 000096 used in state RAM are not transferred.

The additional state RAM data to be sent over multiple scans can also be of any or all of the four reference data types, and must also be specified in multiples of 16. The additional reference data region for each data type starts at the lowest available reference number. For example, if 2048 coils are transferred on every scan (000001... 002048), and you schedule 1024 additional coils for transfer over multiple scans, references 002049... 003072 are used for the additional transfer data.

The additional transfer is handled by specifying the number of scans over which you want to send the additional data. For example, if you specify two scans in which to transfer coils 002049... 003072, then coils 002049... 002560 are sent with coils 000001... 002048 on one scan and coils 002561... 003072 are transferred with coils 000001... 002048 on the next scan.

40 840 USE 106 00 January 2003