Application-Specific Function Blocks - Mitsubishi Electric WS0-CPU0 Operating Manual

Chapter 9
Figure 132:
Function block diagram for
the Reset function block
Table 63:
Parameters of the Reset
function block
155
Logic programming – Function blocks
9.8

Application-specific function blocks

9.8.1 Reset
Function block diagram
General description
The Reset function block can be used to fulfill the normative requirements for safety
applications on acknowledging a manual safety stop and the subsequent request to
restart the application. Typically, each safety logic system of a MELSEC-WS safety
controller contains a Reset function block.
Parameters of the function block
Parameter
Min. reset pulse time
Number of inputs
Release condition fulfilled output
The Release condition fulfilled output displays the result of an AND combination of
all activated Release inputs. It is High if all activated Release inputs are High.
Reset required output
The Reset required output shows by pulsing at 1 Hz that the function block expects a
valid reset pulse at the Reset input so that the Enable output can become High. This
is the case if the Release condition fulfilled output is High, i.e. all activated Release
inputs are High, but the Enable output is still Low. Typically this output is used to
control a signal lamp.
Enable output
The Enable output becomes High, if the Release condition fulfilled output is High
and a valid reset pulse has been detected at the Reset input, provided that all
activated Release inputs remain High.
The Min. reset pulse time defines the minimum required duration of the pulse at the
Reset input. Valid values are 100 ms and 350 ms. If the pulse duration is shorter than
the configured minimum pulse time or longer than 30 s, the pulse is ignored.
The Enable output becomes Low, if one or more Release inputs become Low.
Possible values
 100 ms
 350 ms
2 to 8 (= 1 to 7 Release inputs activated)