Specifications

108
Additional Functions Section 12-6
12.6 Additional Functions
Cyclic Poll Area
In addition to the random read and write access to PLC variables, a memory area
comprising 12 bytes is specified in the application description as cyclic poll area.
This data area must be referenced to a 24-Bit-Integer-Register-Variable. This
variable represents the starting address of the data area. To avoid problems with
the signs, the use of the 24-Bit-Integer-Registers is limited to the lower 2 bytes.
When defining the size in the software, it is only necessary to specify the number of
bytes actually used. The software will then increase this size by the number of
bytes that are not used.
Memory Mapping of the Word-Structured Poll Area
Example: Cyclic data starting with register 100, with a size of 12 bytes having been
defined
High-Byte Mid-Byte Low-Byte
KBS Reserved Register 100
Message-high Message-low Register 101
LED 1 to 4 LED 5 to 8 Register 102
LED 9 to 12 LED 13 to 16 Register 103
LED 17 to 20 LED 21 to 24 Register 104
LED 25 to 28 LED 29 to 32 Register 105
etc.
The high-byte is not used
Parallel Message System
With the parallel message system, individual bits in the controller are assigned
status messages.
This data area must be referenced to a 24-Bit-Integer-Register-Variable. This
variable represents the starting address of the data area. To avoid problems with
the signs, the use of the 24-Bit-Integer-Registers is limited to the lower 2 bytes.
When defining the size in the programming software, it is only necessary to specify
the number of bytes actually used. The software will then increase this size by the
number of bytes that are not used.