Rockwell Automation 440R MSR300 Modular Safety Control System - Manual (Page 13)

MSR300 Safety System Manual
Rockwell Automation
MSR300 Manual.doc Pg 13 of 85
3.1.2.6 Two-Hand Control
• Two-hand control type IIIC ( EN 574)
• Simultaneity detection: 0.5 seconds limit.
The two-hand control function ensures that operators keep their hands clear of a
hazardous area of a machine. It is meant for use with machines such as mechanical and
hydraulic presses. A machine cycle can only be initiated by pressing two momentary
pushbutton switches simultaneously. Switches must fulfill the requirements of EN574 type
IIIC. Releasing one or both pushbutton switches open the output contacts to interrupt the
cycle and stop the machine. The output contacts can be closed again only after the inputs
have released and the pushbutton switches actuated again.
If a machine is operated by more than one person simultaneously, separate two-hand
controls are required for each operator station.
The two-hand operator station should be located far enough from the hazardous area so
that the latter cannot be reached by the operator before the machine stops (after a stop
command is given).
Typical applications of two-hand safety controls are: presses, shears, plastic-molding
machines, etc.
3.1.2.7 Reset
Action
The reset logic of the three Output Groups of the system can be configured for one of the
following modes:
• Automatic reset: The Output Group is active as soon as all input circuits and
feedback loop are closed.
• Manual monitored reset: The Output Group is not active until the reset button has
been operated and then released (and feedback loop closed). This eliminates the
possibility of triggering automatic activation if the reset switch is overridden.
• Manual (non-monitored) reset: The Output Group can be set up for automatic reset
and yet have a reset contact connected in series with the feedback loop. In this
case manual reset is not monitored.
3.1.2.8
Muting (for Robot cell applications)
Muting is the safe, automatic and temporary suspension of an electrosensitive protective
device, in accordance with EN 61496-1 A.7. Muting is typically applied to allow material in
process to be moved into and out of a hazardous area. The presence / movement of such
material can be detected by muting sensors. Typically, muting causes the signal inputs
from safety barriers such as opto-switches or light curtains to be temporarily ignored, -
only as long as the muting sensors detect material in process approaching entry to, or
exit from a machine. MSR300 muting does not monitor material flow but is especially
designed and limited to applications as explained in the Robot cell examples later in this
document (safe position monitoring of the Robot arm).