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• Feldbus Coupler/Controller
Fieldbus Controller 750-806
WAGO-I/O-SYSTEM 750
DeviceNet
In addition, the Controller offers further memory spaces which, however, can-
not be accessed from the fieldbus side:
RAM
The RAM memory is used to create variables not required for com-
munication with the interfaces but for internal processing, such as
computation of results.
The retain memory is a non-volatile memory, i.e. all values are re-
tained following a voltage failure. The memory management is
automatic. In this memory area, flags for the IEC 61131-3 program
are filed together with variables without memory space addressing or
variables which are explicitly defined with "var retain".
Retain
Note
The automatic memory management can cause a data overlap. For
this reason, we recommend not to use a mix of flags and retain vari-
ables.
Code
memory
The IEC 61131-3 program is filed in the code memory. The code
memory is a flash ROM. Once the supply voltage is applied, the
program is transmitted from the flash to the RAM memory. After an
error-free start-up, the PFC cycle starts when the operating mode
switch is turned to its upper position or by a start command from
WAGO-I/O-
PRO
32.