The Shared RAM
134
Operating Manual XCA 1100 / XCA 1200
●
Version 12/17
10.2
Access the Shared RAM
The data structure of the shared RAM is created during the installation
of the PLC or CNC operating system. For pure PLC, only the variable
areas for PLC specification and errors are created (
plcSect
and
errSect
, see below). The PLC program has access to the entire
shared RAM via the global variable
plcMem
(for PLC controllers) or
cncMem
(for CNC controllers). The individual components for read
and write access (e.g. version numbers, error messages, bit signals,
word ranges, NC data, CAN data, etc.) are combined in sections. The
retentive variables (retain) occupy their own sections.
PLC-specific section plcSect
Error section errSect
General section comSect
General section (retain) comSect
System section sysSect
System section (Retain) sysSect
Axis section axSect
Axis section (Retain) axSect
You can access the individual sections and components of the shared
RAM with the
Globale_Variable.Section.Components
notation. For
example, the PLC program can read the version number of the
controller operating software from the
cncMem.plcSect.lOSVersion
variables. For integration of the
shared RAM in the MULTIPROG programming software
page 47.
Visualisation systems have access to the shared RAM via the OPC
interface. The OPC server cannot handle structured variables so the
whole data structure of the shared RAM is represented as a one-
dimensional list. The names are composed of two parts separated by
a "_". The first part is the access path, while the second part is
identical to the component name of the PLC variable. For example,
the version number of the operating system could be read from the
OPC variables
cmpS_lOSVersion
.
10.3
Help about Shared RAM
A more detailed description of the shared RAM structure and all
versions can be accessed via the online help in both MULTIPROG
and the Schleicher dialog.
