Rockwell Automation 1752-L24BBBE SmartGuard 600 Controllers User Manual - Manual (Page 250)

250 Rockwell Automation Publication 1752-UM001E-EN-P - June 2014
Appendix D Function Blocks Command Reference
Configure the local input in the controller as dual channel complementary.
Program Example
Limit switches 1 and 2 connect to muting signal 11 of the muting function block
using an Estop instruction. Limit switches 1 and 2 are set to dual channel
complementary setting for local inputs to evaluate the input data from the two
switches.
Figure 72 - Program Logic
Muting Sequence
The muting sequence for this example is described below.
1. When the machine’s dangerous area is on the same side as the operator,
N.O. limit switch 1 is off and N.C. limit switch 2 is on. In addition, the
light curtain is not obstructed, so the Output Enable signal is on. Muting
Signal 11, which inputs the dual channel complementary signal for limit
switches 1 and 2, goes off.
2. As the robotic arm rotates, limit switch 1 goes on and limit switch 2 goes
off when the dangerous area is opposite the operator. The result of the
Estop instruction, which inputs the dual channel complementary signal for
limit switches 1 and 2, goes on, so muting is enabled, and the muting signal
goes on.
3. At this point, the Output Enable signal is kept on even if the light curtain
is obstructed so the operator can access the work platform.
4. When the operator completes his task and the light curtain is
unobstructed as the robotic arm rotates, the result of the Estop instruction
goes off, the muting status is cleared, and the muting signal goes off.