Glossary
46
© 2010 Wieland Electric GmbH | BA000256 | 12/2012 (Rev. I)
System Functions
OR function and muting function
The off signal of an input function can be bridged with an OR signal. For example, in setup
mode a safety function can be bridged using an enabling button; an OR operation can also
link two safety functions.
The OR function can be implemented by the base module (depending on the function)
or by an input module. It corresponds to an input circuit function with dual-channel
equivalent activation without cross-circuit monitoring.
The muting function is a special case of the OR function (conditional OR). For example,
muting sensors allow a conveyor belt to transport material through a light curtain by briefly
bridging the light curtain function. An ON signal (H-level) is generated only if the internal
output signal of the Reset function
Q
START
has H-level at the beginning of the Muting
function
The muting function in the
samos
base device corresponds to an input circuit function
with dual-channel equivalent activation without cross-circuit monitoring. Muting of a safety
function must not be dependent on a single signal! An output controls the corresponding
muting lamp. This lamp additionally indicates by blinking that the Reset signal is expected at
input S1.
The deactivated enabling input of the associated base module shuts down the outputs
(
Q1..Q4
) switched on by OR or MUTING. The Muting lamp output Q3 stays on during the
Muting function, if function block 3 is selected. When they are subsequently activated, OR
or MUTING mode continues.
___________________________________________________________________________
Bypass function
With a bypass signal an internal OFF signal (L-level) of the Reset function
Q
START
can be
overwritten in the base module. The bypass function is generated by a high-level (see also
the “Reset Function” figure on page 47). It corresponds to an input function with dual-
channel equivalent activation with cross-circuit monitoring.
Bypass is used when the system is to be switched on after a power shutdown but a light
barrier is obstructed by material. Bypass cancels the safety function of the light barrier and
the blockage can be cleared. In normal operation the muting function bridges automatically
(see above).
The bypass signal is limited to 60 s. After the time has expired bypass mode can be
reactivated. After the bypass signal has been cancelled and respectively after 60 s the
enabling outputs are switched off, if the restarting inhibit function is on and the light
curtain was inerrupted. However, any set release time will run in full.
Bypass can be aborted by canceling the bypass instruction on the input module or by a
low signal on the
EN
enabling input on the associated base module. This means, for
example, that a higher-priority emergency stop can shut the machine down during bypass
mode.
After the bypass signal has been cancelled, the internal signal Q
Start
determines the
state of the outputs (see Reset Function on page 47).
The bypass signal should be generated only by a particularly deliberate action by a person
with a view into the system (e.g. by using a lockswitch that automatically returns to off
position or a combination of lockswitch and enabling button).
The starting inhibit on the associated base module is never on when bypass inputs are
active. This means that when voltage is switched on with high potential on the
EN
ENABLE input, the outputs are enabled immediately without additional manual
intervention.
OR
For OR and muting
functions see also page
22.
For the reset function see
page 47.
Muting
Bypass
EXAMPLE
For the input circuit
functions of the input
modules see page 36.
NOTE
Summary of Contents for samos
Page 76: ......
