11 mute sensor pair, 1 the muting function – Banner SC22-3E Safety Controller with Ethernet User Manual
Page 116
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 device. This circuit can detect a
short circuit between channels. In the actuated condition (e.g., S1
OFF/S2 ON as shown), a short across the closed contact can
cause the response time to increase based on the debounce time.
In this situation, the response time could be longer than specified,
based on the (selected) debounce time, see section
ON
OFF
S1
S2
2x Complementary (4 or 5 terminals): This circuit can meet ISO
13849-1 category 4 requirements depending on the design and in-
stallation of the device(s). This circuit can detect a short circuit be-
tween channels. In the guard closed condition (e.g., S1 open/S2
closed) a short across the closed contact can cause the response
time to increase based on the debounce time. In this situation, the
response time could be longer than specified, based on the (selec-
ted) debounce time, see section
4.3.2 Safety Input Device Proper-
on page 28.
24V
S1
S2
2x Complementary (PNP device): This circuit can meet ISO
13849-1 category 4 requirements depending on the design and in-
stallation of the device(s). This circuit can detect a short circuit be-
tween channels. In the actuated condition (e.g., S1 OFF/S2 ON) a
short across the closed contact can cause the response time to in-
crease based on the debounce time. In this situation, the response
time could be longer than specified, based on the (selected) de-
bounce time, see section
4.3.2 Safety Input Device Properties
page 28.
ON
OFF
ON
OFF
S1
S2
10.11 Mute Sensor Pair
10.11.1 The Muting Function
The user is required by OSHA and ANSI to arrange, install, and operate the safety system so as to protect personnel and mini-
mize the possibility of defeating the safeguard.
To mute the primary safeguard appropriately, the design of a muting system must:
1. Identify the non-hazardous portion of the machine cycle,
2. Involve the selection of the proper muting devices, and
3. Include proper mounting and installation of those devices.
The Controller can monitor and respond to redundant signals that initiate the mute. The mute then suspends the safeguarding function by
ignoring the state of the Input Device that the muting function has been assigned to; e.g., this allows an object or person to pass through
the defined area of a safety light screen without generating a stop command. (This should not be confused with blanking, which disables
one or more beams in a safety light screen, resulting in larger resolution.)
The mute may be triggered by a variety of external devices. This feature provides a variety of options (see the following sections) to tailor
the System to the requirements of a specific application.
A pair of muting devices must be triggered simultaneously (within 3 seconds of one another). This reduces the chance of common mode
failures or defeat. Directional muting, in which sensor pair 1 is required to be blocked first, also can reduce the possibility of defeat.
See section
on page 37 for more information.
SC22-3/-3E Safety Controller Instruction Manual
116
www.bannerengineering.com - tel: 763-544-3164
P/N 133487 rev. C