Banner SC22-3E Safety Controller with Ethernet - Manual (Page 119)

Dual-Channel (4 terminals): This circuit can meet ISO 13849-1
category 2, 3, or 4 requirements depending on the installation of
the mute device(s). This circuit can detect a short circuit between
channels or to another source of power.
Complementary (2 or 3 terminals): This circuit can meet ISO
13849-1 category 2, 3, or 4 requirements depending on the safety
rating and the installation of the output device. This circuit can de-
tect a short circuit between channels. The 3-terminal hookup can
detect a short circuit to another source of power, when the contact
is closed. 24V
Complementary (PNP device): This circuit can meet ISO
13849-1 category 2, 3, or 4 requirements depending on the safety
rating and the installation of the output device. This circuit can de-
tect a short circuit between channels. ON OFF
10.11.4 Mute Enable (ME)
The Mute Enable input is a non-safety-rated input. When the input is closed, the Controller will allow a mute condition to occur; opening
this input while the System is muted will have no effect.
Typical uses for Mute Enable include:
• To allow the machine control logic to create a “window” for muting to begin;
• To inhibit muting from occurring; or
• To reduce the chance of unauthorized or unintended bypassing or defeat of the safety system.
Simultaneity Timer Reset Function
The Mute Enable input can also be used to reset the simultaneity timer of the mute inputs. If one input is active for longer than three
seconds before the second input becomes active, the simultaneity timer will prevent a mute cycle from occurring. This could be due to a
normal stoppage of an assembly line that may result in blocking one mute device and the simultaneity time running out.
If the ME input is cycled (closed-open-closed) while one mute input is active, the simultaneity timer is reset, and if the second mute input
becomes active within three seconds, a normal mute cycle begins. The timing requirement for the closed-open-closed is similar to the
manual reset function. Initially, the input needs to be active (closed) for longer than 1/4 second, then open for longer than 1/4 second, but
not longer than 2 seconds, and then must reclose to reset the simultaneity timer. The function can reset the timer only once per mute
cycle (i.e., all mute inputs M1–M4 must open before another reset can occur).
10.11.5 Mute Lamp Output (ML)
Some applications require that a lamp (or other means) be used to indicate when the safety device (e.g., light screen) is muted; the
Controller provides for this through the Status Outputs. If a monitored output signal is required (see Caution below), Status Outputs O9
and O10 can be configured for a monitored output. The monitored output will prevent the initiation of a mute after an indicator failure is
detected. If the application requires compliance with UL 61496, Lamp Monitoring must be selected and the lamp used must meet applica-
ble requirements.
WARNING: . . . Mute Status Must Be Readily Observed
Indication that the safety device is muted should be provided and be readily observable.
Failure of this indication should be detectable and prevent the next mute, or operation of the indicator should be
verified at suitable intervals.
SC22-3/-3E Safety Controller Instruction Manual
P/N 133487 rev. C www.bannerengineering.com - tel: 763-544-3164 119