74
Function Description
WAGO-I/O-SYSTEM 750
750-806 Fieldbus Controller DeviceNet
TM
Manual
Version 2.0.0
Avoid writing to one output at the same time!
Avoid simultaneous writing to an output either by using instance 11 of the static
assemblies (see section “Fieldbus Communication” > … > “Additional Assembly
Instances 10 and 11”) or by using the dynamic assembly (see section
“Programming PFC with WAGO-I/O-PRO” > “Special DeviceNet
TM
Characteristics of the Fieldbus Controller” > … > “Dynamic Assembly”).
Other memory areas are also provided in the fieldbus controller, some of which
cannot be accessed by the fieldbus side, however:
•
Data memory (64 kByte)
The data memory is a volatile RAM memory for creating variables that are
not required for communication with the interfaces, but rather for internal
processing procedures, such as calculation of results.
•
Program memory (128 kByte)
The IEC-61131-3 program is stored in the program memory. The code
memory is a Flash ROM. When power is switched on, the program is
transferred from the flash to the RAM memory. After error-free run-up, the
PFC cycle starts with the mode selector switch at the top position, or on the
Start command from the WAGO-I/O-
PRO
.
•
NOVRAM Remanent memory (8 kByte)
The remanent memory is a non-volatile memory; i.e., all values of flags and
variables, that are explicitly defined by “var retain”, are retained even after a
loss of power. Memory management is performed automatically. The 8 KB
memory area is used jointly for flags and retain variables.
Markers are only remanent under “var retain”!
Please note that the bit memory is only retentive if you have declared it as such
under “var retain”.
