Retention; Requirements - Eaton easySafety Manual

02/16 MN05013001Z EN

Retention

Plant and machine controls require the possibility to reten-
tively set operating states or actual values, i.e. the values
should be retained safely even after the power supply of a
machine or plant has been switched off and should be left
unchanged until the actual value is overwritten.
The following operands and function blocks of the standard
circuit diagram can be set retentively:
• Markers.
• Counter function blocks.
• Data function block.
• Timing relays.
Hours-run counter
easySafety features 4 retentive operating hours counters.
They are always retentive and can only be selectively deleted
with a reset command.
Data volume, retentive data
The maximum memory range for retentive data is 200 bytes
(operating hours counters are not included).
Markers
A user-definable and contiguous marker byte range can be
declared as retentive.
Counters
All C.. function blocks can be operated with retentive actual
values.
Data function blocks
A user-definable consistent function block DB range can be
operated with retentive actual values.
Timing relays
A user-definable and contiguous range for timing relays T
can be run with retentive actual values.

Requirements

In order to make data retentive, the relevant markers and
function blocks must have been declared as retentive.
Retention
597