Another Example Another Example Another Example i SENSOR

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Another Example

Another Example

Another Example

Another Example

Another Example /i. SENSOR • i. RET S 0 o. CYL=0 i. SENSOR o.

Another Example /i. SENSOR • i. RET S 0 o. CYL=0 i. SENSOR o. CYL=0 S 2 i. EXT S 1 o. CYL=1

Example #2 State Diagram /i. SENSOR • i. RET S 0 o. CYL=0 i.

Example #2 State Diagram /i. SENSOR • i. RET S 0 o. CYL=0 i. SENSOR o. CYL=0 S 2 i. EXT S 1 o. CYL=1 Curr. St i. SENSOR i. EXT i. RET | Next. St ------------------S 0 0 X X | S 0 1 X X | S 1 X 0 X | S 1 X 1 X | S 2 0 X 0 | S 2 0 X 1 | S 0 S 2 1 X X | S 2

Example #2 State Diagram /i. SENSOR • i. RET S 0 o. CYL=0 i.

Example #2 State Diagram /i. SENSOR • i. RET S 0 o. CYL=0 i. SENSOR o. CYL=0 S 2 i. EXT S 1 o. CYL=1 Curr. St i. SENSOR i. EXT i. RET | Next. St ------------------S 0 0 X X | S 0 1 X X | S 1 X 0 X | S 1 X 1 X | S 2 0 X 0 | S 2 0 X 1 | S 0 S 2 1 X X | S 2 c. S 0 = c. S 2 • /i. SENSOR • i. RET + c. S 0 • /i. SENSOR + /c. S 0 • /c. S 1 • /c. S 2 c. S 1 = c. S 0 • i. SENSOR + c. S 1 • /i. EXT c. S 2 = c. S 1 • i. EXT + c. S 2 • /(/i. SENSOR • i. RET) = c. S 1 • i. EXT + c. S 2 • (i. SENSOR + /i. RET)

State Machines in Ladder Logic • Pure relay logic - traditional design: – –

State Machines in Ladder Logic • Pure relay logic - traditional design: – – 2 states = 1 coil 3 -4 states = 2 coils 5 -8 states = 3 coils, etc. difficult to debug, modify and document • Pure relay logic - “one-hot” design – 1 coil per state – easier to debug, modify, and document – watch out for “illegal” states • RLL-Plus – – “Stages” JMP “coils” easiest to write and maintain not available in all brands of PLC’s

Example #2 State Diagram /i. SENSOR • i. RET S 0 o. CYL=0 i.

Example #2 State Diagram /i. SENSOR • i. RET S 0 o. CYL=0 i. SENSOR o. CYL=0 S 2 i. EXT S 1 o. CYL=1 c. S 0 = c. S 2 • /i. SENSOR • i. RET + c. S 0 • /i. SENSOR + /c. S 0 • /c. S 1 • /c. S 2 c. S 1 = c. S 0 • i. SENSOR + c. S 1 • /i. EXT c. S 2 = c. S 1 • i. EXT + c. S 2 • i. SENSOR + c. S 2 • /i. RET)

Ex #2 - RLL-Plus Stages /i. SENSOR • i. RET S 0 o. CYL=0

Ex #2 - RLL-Plus Stages /i. SENSOR • i. RET S 0 o. CYL=0 i. SENSOR o. CYL=0 S 2 i. EXT S 1 o. CYL=1

Multi-state Example • When sensor detects block; clamp block, drill hole, shift, drill 2

Multi-state Example • When sensor detects block; clamp block, drill hole, shift, drill 2 nd hole, shift back, release clamp

Inputs and Outputs • • i. SENSOR block present • o. DRILL start drilling

Inputs and Outputs • • i. SENSOR block present • o. DRILL start drilling i. DRILLDN drill is down • o. CLAMP activate clamp i. DRILLUP drill is up • o. SHIFT shift block i. CLAMPED fully holder clamped • i. RELEASED fully unclamped • i. POS 1 unshifted • i. POS 2 shifted

State Diagrams • One state per “action” • Look for “wait” states needed

State Diagrams • One state per “action” • Look for “wait” states needed

State Diagram

State Diagram

RLL-Plus

RLL-Plus

RLL-Plus

RLL-Plus

RLL-Plus

RLL-Plus