Memory size

The entire available memory for the external variables of each channel has to be defined before start-up of the control:

• For TwinCAT systems the dimensioning is defined in the System Manager (CNCTask-GEO) on the HLI mask under the VE entry.
• For all other systems the size of the VE memory is defined by the parameter P-STUP-00037 (ext_var_max) in the start-up list [STUP].

The here-defined value determines the number of 24 bytes blocks, of which the VE memory of each channel consists. The global external variables (cross-channel scope) use an own memory of equal size. The reserved VE memory of each channel and the global one has to be larger than the used memory area, defined by the memory layout (see following chapter).

If the available memory is not enough for the external variables, configurated in the list, the error message P-ERR-21148 is generated. In this case either the reserved memory has to be extended or the size and number of configurated external variables has to be decreased.