Chapter 9
230
Logic programming – Function blocks
Contact monitoring
The input signals for the Overrun cam input, Upstroke cam input and the Drive
released input have to accord with Figure 215 and the following rules.
(1) The overrun must begin during the upstroke phase: The rising edge at the
Overrun cam input (Low-High transition) must occur while the Upstroke cam
input is High.
(2) The overrun must end after the end of the upstroke phase: The falling edge at the
Overrun cam input (High-Low transition) must occur when the Upstroke cam
input is Low.
(3) The upstroke phase must begin after the overrun has ended: The rising edge at
the Upstroke cam input (Low-High transition) must occur while the Overrun cam
input is Low.
(4) The upstroke phase must end during the overrun: The falling edge at the Upstroke
cam input (High-Low transition) must occur while the Overrun cam input is High.
If at least one of these conditions is not fulfilled during operation, the Enable output
becomes Low and the Contact error output becomes High.
A valid sequence to fulfill the conditions is as follows:
0) Start condition: Overrun cam input = High, Upstroke cam input = Low
1) Overrun cam input: High Low
2) Upstroke cam input: Low High
3) Overrun cam input: Low High
4) Upstroke cam input: High Low
Observe the relevant safety standards and regulations!
All safety related parts of the installation (cabling, connected sensors and actuators,
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 Upstroke cam, if the Upstroke output is
used for upstroke muting, e.g. in combination with a press cycle control function block.
Figure 215:
Contact monitoring with the
Eccentric press contact
function block
ATTENTION
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