Pixsys TD320, Руководство пользователя

Страница: 27 / 75

27
bits, words or double words. In the last case, the number of double
words always makes reference to the organization by words,
therefore in order to access consecutive double word variables it is
necessary to increment by 2.
The memorized values are maintained even in the absence of
power thanks to the rechargeable battery pad. Once charged, the
battery maintains memorized data for approximately 6 months.
VW0
VW1
VW2
VW3
VW4
VW5
VD0
VD2
VD4
VD1
VD3
ACCESS WORD
ACCESS DOUBLE WORD
5.2 Area of Special Marker SM
Area special marker SM is the memory area used to retain all the
data necessary for the Ladder program to interact with the TD320
hardware.
Some data are initialized at the start with default values indicated
in the table below. In this area are the storage words that manage
the events relative to the graphics, the PLC control bits and the
setup for the serial ports of communication.
The table below describes the content of each single location of
the special marker area, indicating the address for access through
the ModBus protocol and the operation allowed at this location (R
= read, W = write, R/W = read/write). The bits and words that do
not appear in the tables are not used.