Chapter 9
Note
Figure 204:
Valid muting sequence
using the basic configuration
setting (C1 input: without,
Override input: without,
Conveyor input: without)
221
Logic programming – Function blocks
Equations and prerequisites for calculating the distance:
v × 2 × T
L
1
IN Muting sensor
v × t > L
+ L
1
3
L
< L
2
3
T
< T
IN Light curtain
IN Muting sensor
Where ...
L
= Distance between the inner sensors (layout symmetrical to the detection
1
area of the ESPE)
L
= Distance between the outer sensors (layout symmetrical to the detection
2
area of the ESPE)
L
= Length of the material in conveyor direction
3
v
= Velocity of the material (e.g. of the conveyor belt)
t
= Set total muting time [s]
T
, T
IN Light curtain
IN Muting sensor
in the MELSEC-WS safety controller (See the Safety Controller User's Manual.)
In this example the material can either be moved in both directions or a fixed
direction of transportation can be defined as follows:
– With the optional input C1. If used, the C1 input always has to be activated
before both muting sensors of the first sensor pair (e.g. A1 and A2) become High.
– By means of the Direction detection configuration parameter
The sensor layout shown in this example is suitable for all types of sensors.
Avoid mutual interference of the sensors.
Increase the protection against manipulation and the safety level by using the
following configurable functions:
– concurrency monitoring
– monitoring of the total muting time
– muting end via ESPE
– sequence monitoring
Information on wiring can be found in Section 9.10.3.
Sequence/timing diagram
The function block requires that a valid muting sequence takes place. Figure 204
shows an example of a valid muting sequence based on the basic parameter setting
for this function block.
= Response time of the light curtain or the muting sensors