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Rockwell Automation 1772-LP3 PLC - 2/30 Programmable Controller Programming and Operations Manual User Manual

Page 144

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Output Override and I/O Update Instructions

Chapter 7

7Ć2

Figure 7.1

MCR and ZCL Zone Programming

|ą|

( ZCL )

|ą|

( ą)

|ą|

| / |

| / |

( ą)

|ą|

|ą|

( ą)

|ą|

|ą|

|ą|

|ą|

|ą|

( ZCL )

|ą|

( ą)

( ą)

| / |

|ą|

( MCR )

|ą|

( ą)

|ą|

| / |

| / |

( ą)

|ą|

|ą|

( ą)

|ą|

|ą|

|ą|

|ą|

|ą|

( MCR )

|ą|

( ą)

( ą)

| / |

Start Fence

Unconditional End Fence

Start Fence

Unconditional End Fence

When ZCL zone is false

all outputs remain in

their last state.

When MCR zone is false

nonretentive outputs are

deĆenergized.

The MCR and ZCL instructions control the zoned outputs differently:

MCR — When false, all nonretentive outputs within the MCR zone are

de-energized or turned off.

ZCL — When false, the outputs within the ZCL zone are left in their

last state: either on or off.