Mitsubishi Electric WS0-CPU0 - Page 224

Chapter 9
221
Logic programming – Function blocks
Equations and prerequisites for calculating the distance:
L
1
 v × 2 × T
IN Muting sensor
v × t > L
1
+ L
3
L
2
< L
3
T
IN Light curtain
< T
IN Muting sensor
Where …
L
1
= Distance between the inner sensors (layout symmetrical to the detection
area of the ESPE)
L
2
= Distance between the outer sensors (layout symmetrical to the detection
area of the ESPE)
L
3
= Length of the material in conveyor direction
v = Velocity of the material (e.g. of the conveyor belt)
t = Set total muting time [s]
T
IN Light curtain
, T
IN Muting sensor
= Response time of the light curtain or the muting sensors
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.
Note
Figure 204:
Valid muting sequence
using the basic configuration
setting (C1 input: without,
Override input: without,
Conveyor input: without)