The Shared Memory
80
Operating Manual ProNumeric XCI 600 Version 07/16
10.5
Further Background Information on Shared Memory
The following elements are added or updated when inserting the shared
memory in a PLC project:
The
SharedMemory_Types
data type worksheet; the data structure of the
shared memory is declared here.
The global variables
plcMem
(for PLC controllers) or
cncMem
(for CNC
controllers). See worksheet
Global_Variable
s, group
SharedMemory_Variables
.
These variables represent the complete non-retentive (non retain) section
of the shared memory. The PLC program can access the individual
components (variables) of the shared memory using dot notation as
explained above.
With shared memory version 8 or higher, there is a retentive (retain)
section of the shared memory as well as the non-retentive section. Unlike
the non-retentive section, the values of the variables of this section are
retained after switching off the controller. For this purpose, the global
variable
cncRMem
is additionall inserted.
The global variables
cmpS..., cmeS..., cmcS..., cmsS...,
cmaS...
. See worksheet
Global_Variables
, groups
PLC_Common
,
CNC_Common
,
CNC_System_x
(x stands for the number of the CNC
sub-system. Such a group exists with system-specific variables for each
sub-system) and
CNC_Axis_y
(y stands for the number of CNC axis.
Such a group exists with axis-specific variables for each CNC axis).
These variables are provided for the visualisation systems or similar
programs to access the shared memory. They provide all the shared
memory via the OPC interface. These variables provide the shared
memory in an unstructured form. Only simple data types (BOOL, DINT,
REAL, STRING) and fields of simple data types are used. This procedure
is required because structured data (like the ones that variables
plcMem
and
cncMem
contain) can not be transferred via the OPC interface.
