03 Processing Grafcet

Processing station Function chart

DE 01/04

Function chart according to DIN EN 60848

The following figure displays a comparison of symbols of DIN 40719-6 (1992-02) and symbols of DIN EN 60848 (2002-12).

S

N

D

delay t=3s

9

3s/X9 "delay"

Left: DIN 40719-6; right: DIN EN 60848

Note The standard DIN 40719-6 is valid until 2005-04.

2

DIN 40719-6 1992-02

Diagrams, charts, tables; rules for function charts; (IEC 848 modified)

DIN EN 60848 2002-12

GRAFCET specification language for sequential function charts; (IEC 60848)

© Festo Didactic GmbH & Co. KG • MPS

Function chart Processing station

sequential function chart according to DIN EN 60848 (IEC 60848) for the Processing station 1-bit-link

1

Start

station is reset and in initial position

station is not reset 2

"reset" indicator light

turn on "reset" indicator light

"reset" button pressed 3

move station to initial position

initial position

drill in upward position 4

turn rotary indexing table

rotary indexing table to initial position

station in initial position 5

reset ok

B 14

set flag "reset finished" flag "reset finished" is set

6

empty step: cycle start

flag "start" is not set 7

"start" indicator light

flag "start" is set

turn on "start" indicator light

flag "start" is set 8

station not occupied

workpiece available 9

station occupied

station occupied

3s/X9 "delay" A 10

© Festo Didactic GmbH & Co. KG • MPS

3

Function chart Processing station

A9 10

empty step: downstream station free

downstream station free 11

rotary indexing table

turn on rotary indexing table

rotary indexing table not positioned 12

empty step: program synchron.

rotary indexing table positioned 13

empty step: delay

1s/X13 "delay"

M20

"drill hole checking"

M30

"drilling"

M40

"workpiece output"

macro steps M20, M30 and M40 completed 14

cycle end

set flag "cycle end" transferring the information "workpiece orientation"

"bit shifting see below"

flag "cycle end" is set B6 Sample of the bit shifting of flag "workpiece orientation" After each process the bits and the rotary indexing table are shifted by one step. The information "workpiece orientation ok" (bit = 0) respectively "workpiece orientation not ok" (bit = 1) is acquired during the "dill hole checking" (M20) and is shifted to and used by "drilling" (M30) and "workpiece output" (M40). Sequence of inserted workpieces: "A", "B", "C", "D" ... whereas "B" is a bad part. position of the rotary indexing table

flag "workpiece orientation" (flag word)

pos. 1 checking

pos. 2 drilling

pos. 3 output

BIT 1

BIT 2

BIT 3

1

–

–

–

–

–

–

2

A

–

–

0

–

–

3

B

A

–

1

0

–

4

C

B

A

0

1

0

5

D

C

B

0

0

1

y y

y y

y y

y y

y y

y y

y y

4

© Festo Didactic GmbH & Co. KG • MPS

Function chart Processing station

macro step M20 "parallel branch drill hole checking" E20

empty step: parallel branch drill hole checking

"entry point for macro step M20"

workpiece available 21

checking workpiece orientation

no workpiece available

turn on verifying magnet

3s/X21 and workpiece orientation not ok

3s/X21 and workpiece orientation ok 23

22

workpiece orientation ok

turn off verifying magnet reset flag "workpiece orientation" bit 1

verifying magnet is off

S20

flag "start" is not set

empty step: end of parallel branch drill hole checking

workpiece orientation not ok

turn off verifying magnet set flag "workpiece orientation" bit 1

verifying magnet is off

"exiting point for macro step M20"

© Festo Didactic GmbH & Co. KG • MPS

5

Function chart Processing station

macro step M30 "parallel branch drilling" E30

empty step: parallel branch drilling

"entry point for macro step M30"

workpiece available and flag "workpiece orientation" bit 2 is not set 31

fixate workpiece

fixate workpiece

(no workpiece available) or (workpiece available and flag "workpiece orientation"bit 2 is set)

flag "start" is not set

workpiece is fixed 32

lower drilling unit

drill on

turn on drill drilling untit lowered 33

raise drilling unit

drill off

turn off drill drilling unit raised 34

free workpiece

unfix workpiece

workpiece is unfixed

S30

empty step: end of parallel branch drilling

6

"exiting point for macro step M30"

© Festo Didactic GmbH & Co. KG • MPS

Function chart Processing station

macro step M40 "parallel branch workpiece output" E40

empty step: parallel branch workpiece output

"entry point for macro step M40"

flag "workpiece orientation" bit 3 is set

flag "workpiece orientation" bit 3 is not set 41

workpiece orientation ok

42

eject workpiece

workpiece orientation not ok

flag "start" is not set

turn on "start" indicator light turn on "workpiece orientation not ok" ind. light

1s/X41 "delay"

S40

empty step: end of parallel branch workp. output

error acknowledged

"exiting point for macro step M40"

© Festo Didactic GmbH & Co. KG • MPS

7

Function chart Processing station

8

© Festo Didactic GmbH & Co. KG • MPS