Mitsubishi Electric WS0-CPU0 Operating Manual page 241

Chapter 9
Logic programming – Function blocks
Additionally, the number of BDC signals (Low-High-Low) must be according to the
configured value, i.e. either exactly one or any value between 0 and 2.
0 BDC signals per cycle 1 BDC signal per cycle 2 BDC signals per cycle
Figure 224:
Timing diagrams for 0, 1 and 2 BDC signals per cycle
If one or more of the conditions mentioned above is not fulfilled during operation, the
Enable output becomes Low and the Contact error output becomes High.
Observe the relevant safety standards and regulations!
All safety related parts of the installation (cabling, connected sensors and actuators,
ATTENTION
configuration settings) must be according to the relevant safety standards (e.g. IEC
62061 or EN/ISO 13849-1 or Type C standards such as EN 692 and EN 693) and
regulations. Only safety-relevant signals may be used in safety-relevant logic. Ensure
that the application fulfills all applicable standards and regulations!
This needs to be considered especially for the BDC, if the Upstroke output is used for
upstroke muting, e.g. in combination with a press cycle control function block.
If the Number of BDC signals per cycle is configured to 0-2 (e.g. hydraulic press),
the function block's error detection is reduced and not all input errors can be detected
(e.g. stuck-at-low at the BDC input).
In order to fulfill the safety standards it may be necessary to use tested switches for
the cam input signals, each with different test sources. To use different test sources
for the cam signals, the TDC, BDC and Overrun cam inputs need to be connected to
different WS0-XTDI or WS0-XTIO modules.
One WS0-XTDI has 2 test sources only, even if it has eight test output terminals.
Note
238