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Introduction
1.16 Override
The Override function allows the user to manually force the OSSD outputs ON for
10 seconds in a situation such as an object becoming "stuck" in the defined area
of a safety light screen after the mute ends (e.g., a car body on a transfer line
entering a work cell). The feature is intended to allow the user to "jog" the part
out of the defined area.
This input requires two normally open switches, both of which must be closed
within 3 seconds of each other. The Override cycle will last a maximum of 10
seconds, after which the Override input must be released for at least 3 seconds
prior to the next Override cycle. An Override can be initiated only after tripping of
the MSSI inputs causes the Module to latch its OSSDs OFF.
NOTE: A stop command issued by the USSI cannot be overridden.
When Override is used, the following precautions must be taken:
- Prevent exposure to any hazard during an Override cycle,
- Provide a readily observable indication of an Override, and
- Provide supplemental safeguarding, per NFPA79 (Section 9.15) and
IEC/EN60204-1 (Section 9.2.4).
The Override switches must be supervised and must prevent automatic opera-
tion. Also, one or more of the following must be true:
- Motion is initiated by a hold-to-run or similar device,
- If a portable control station (e.g., an enabling device) with an emergency stop
device is used, motion may be initiated only from that station,
- Motion, speed, or power of the machine is limited, or
- The machine's range of motion is limited.
1.17 One-Way/Two-Way Muting
One-way (directional) muting allows the safeguard to be muted only if mute
devices are actuated in the order M1, M2, (mute initiated), M3, and M4. This
method allows for a single-direction material flow and reduces the possibility of
intentional defeat of the muting devices.
Two-way (non-directional) muting allows the safeguard to be muted any time the
actuation of M1-M2 or M3-M4 meets the 3-second simultaneity requirement.
This allows the flow of material from either direction (two-way material flow).
NOTE: When using four mute devices (M1, M2, M3 and M4), in order to extend
the mute until the light screen is clear, the object must activate all four of
the devices at one time during the mute cycle.
1.18 Designated and Qualified Persons
For the purposes of this manual, the following definitions apply:
Designated Person: A person or persons identified and designated in writing, by
the employer, as being appropriately trained and qualified to perform a specified
checkout procedure.
Qualified Person: A person or persons who, by possession of a recognized
degree or certificate of professional training, or who, by extensive knowledge,
training, and experience, has successfully demonstrated the ability to solve prob-
lems relating to the implementation of this safety system.
Buy: www.ValinOnline.com | Phone 844-385-3099 | Email: CustomerService@valin.com
MM-TA-12B Muting Module
Instruction Manual
WARNING . . .
Limit Use of
Override Function
The Override function is not for
machine setup or production; it is
to be used only to clear the pri-
mary safety device, such as if
material becomes "stuck" in the
defined area of a safety light
screen.
When Override is used, it is the
user's responsibility to install and
use it according to current stan-
dards (see Appendix C).
In addition, the requirements listed
in standards NFPA79 (Section 9.15)
or IEC/EN60204-1 (Section 9.2.4)
must be satisfied.
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