Rockwell Automation 440C Guardmaster 440C-CR30 Configurable Safety Relay User Manual - Manual (Page 53)

Rockwell Automation Publication 440C-UM001C-EN-P - November 2014 53
Safety Monitoring Functions Chapter 9
You can use the default Discrepancy Time and Input Filters or choose to modify
these settings.
The CR30 safety relay has three distinct types of muting, where the sequence and
timing of signals that are monitored by the CR30 allows objects to pass through
the light curtain without shutting down the machine process. The three types
are:
• 2-sensor T-Type
• 2-sensor L-Type
• 4-sensor
2-Sensor T-Type Muting
The sensors and light curtain form the shape of an upside down “T”, when
viewed from the side. The muting sensors (MS) are mounted to form an “X”
sensing pattern where the sensing beams cross near the center of the light curtain
(LC).
Figure 46 - 2-Sensor T-Type Muting Arrangement
The material must first break the two muting sensors and then the light curtain.
The order in which the muting sensors are block is not critical, but the
synchronization time (the time between block one sensor and the other sensor)
must be met. The muting lamp turns on when both sensors are blocked and the
light curtain is muted. The conveyor can move in the forward or reverse
direction.
In the example below, the OSSD outputs of the light curtain are connected to
terminals 00 and 01. The two muting sensors are connected to terminals 02 and
03. The momentary, normally open override switch is connected between
terminals 12 to 04 to take advantage of pulse testing. Contactor K1 and K2,
which provide power to the conveyor (and to other hazards), are connected to
terminals 18 and 19.
The muting lamp is connected to terminal 13; this terminal should be configured
with no pulse testing. Filament lamps will not be affected by pulse testing, but
LED lamps may appear to flicker if pulse testing is enabled.
Machine
MS1 MS2
LC
Muting Lamp
Material Conveyor