I created the below "conceptualized" PLC logic for a 40 Hp pump that was to be controlled from a Foxboro I/A Series DCS through an Allen-Bradley PLC-5/60. The PLC-5 communicated with the pump's 1336 VFD through a DeviceNet connection. The actual speed command was transferred elsewhere in logic.
------------------------------------------------------------------------------------------------------------------------------------
|********************************************************************* |
|READY RUNG- PUMP IS READY TO OPERATE IF THERE IS NO DEVICENET |
|MALFUNCTION AND SEAL WATER FLOW IS SUPPLIED |
|********************************************************************* |
|DNET MALF LVL HIGH LOW SEAL READY |
|CLNR CONE SPIRAL WTR FLOW CLNR CONE |
|FEED FEED PUMP CLNR CONE FEED |
|PUMP BOX FEED PUMP PUMP |
| N:A N:B N:C N:D |
41|----|/|-----+----|/|-----+----|/|-----+-+----------------------------------------------------------------------------( )-----|
| 7 | 9 | 1 | | 0 |
| | |DNET RUNNING| | |
| | |CLNR CONE | | |
| | |FEED PUMP | | |
| | | N:A | | |
| | +----| |-----+ | |
| | 1 | |
| |BYPASS INT | |
| |CLNR CONE | |
| |FEED | |
| |PUMP | |
| | N:E | |
| +----| |--------------------+ |
| 2 |
|DCS START/ DN AUTO DN RUNNING SEQUENCE |
|STOP CLNR CONE START CLNR CONE START |
|CLNR CONE FEED PUMP ONE FEED PUMP CLNR CONE |
|FEED PUMP SHOT FEED PMP |
| N:E N:A BF N:A N:G |
42|----| |---------| |-------[ONS]-------|/|-----------------------------------------------------------------------------(L)----|
| 0 15 224 1 0 |
| SEQUENCE |
| DN STOP START |
| CLNR CONE CLNR CONE |
| FEED PUMP FEED PMP |
| N:H N:G |
43|-+----| |-----+-------------------------------------------------------------------------------------------------------(U)----|
| | 0 | 0 |
| |DN RUNNING | |
| |CLNR CONE | |
| |FEED PUMP | |
| | N:A | |
| +----| |-----+ |
| 1 |
|******************************************************************* |
|START TIMER TIMES A MOMENTARY START SIGNAL ON COMMAND FROM THE DCS |
|******************************************************************* |
| SEQUENCE LOW FLOW READY |
| START SEAL WTR SEAL WTR DN STOP CLNR CONE |
| CLNR CONE CLNR CONE START CLNR CONE FEED START |
| FEED PMP FEED PUMP ONE SHOT FEED PUMP PUMP TIMER |
| N:G N:L BF N:H N:D +--TON-----------+ |
44|-+----| |-----+----| |----+----[ONS]---+-----|/|--------| |------------------------------------------|Timer On Delay |-(EN)-|
| | 0 | 1 | 308 | 0 0 |Timer: T:J | |
| | | | | |Base (SEC): 1.0|-(DN) |
| | | | | |Preset: 5| |
| | | | | |Accum: 0| |
| | | | | +----------------+ |
| | +-----------+ | |
| |DCS AUTO SEQUENCE | |
| |SEAL WTR START | |
| |SUPPLY VLV CLNR CONE | |
| | N:M N:G | |
| |----| |---------| |------------------| |
| | 4 0 | |
| | T:J | |
| +----| |------------------------------+ |
| TT |
| DN START |
| CLNR CONE |
| FEED PUMP |
| T:J N:H |
45|----| |---------------------------------------------------------------------------------------------------------------( )----|
| TT 1 |
|******************************************************************** |
|STOP TIMER TIMES A MOMENTARY STOP SIGNAL ON COMMAND FROM THE DCS |
|OR WHEN NOT READY |
|******************************************************************** |
| DCS START/ DN RUNNING |
| STOP STOP CLNR CONE |
| CLNR CONE ONE FEED PUMP STOP |
| FEED PUMP SHOT TIMER |
| N:E BF N:A +--TON-----------+ |
46|-+----| |--------[ONS]-------| |-----+---------------------------------------------------------------|Timer On Delay |-(EN)-|
| | 0 225 1 | |Timer: T:K | |
| | | |Base (SEC): 1.0|-(DN) |
| | | |Preset: 5| |
| | | |Accum: 0| |
| | | +----------------+ |
| | T:K | |
| +----| |----------------------------+ |
| TT |
| DN STOP |
| CLNR CONE |
| FEED PUMP |
| T:K N:H |
47|-+----| |-----+-------------------------------------------------------------------------------------------------------( )----|
| | TT | 0 |
| |READY | |
| |CLNR CONE | |
| |FEED | |
| |PUMP | |
| | N:D | |
| +----|/|-----+ |
| 0 |
|************************************************************************ |
|THE NEXT FOUR RUNGS COPY DEVICENET INPUTS AND OUTPUTS INTO AND OUT OF |
|INTEGER FILES FOR COMMUNICATION WITH DCS |
|************************************************************************ |
|DN RUNNING RUNNING |
|CLNR CONE CLNR CONE |
|FEED PUMP FEED |
| PUMP |
| N:A N:D |
48|----| |---------------------------------------------------------------------------------------------------------------( )----|
| 1 2 |
|DN MALF FAIL |
|CLNR CONE CLNR CONE |
|FEED FEED |
|PUMP PUMP |
| N:A N:D |
49|----| |---------------------------------------------------------------------------------------------------------------( )----|
| 7 4 |
|DN AUTO |
|CLNR CONE |
|FEED PUMP |
| N:A N:D |
50|----| |----------------------------------------------------------------------------------------------------------------( )---|
| 15 1 |
| DCS CLEAR DCS CLEAR |
| VFD FAULT VFD FAULT |
| CLNR CONE CLNR CONE |
| FEED PUMP FEED PUMP |
| N:E N:H |
51|-+----| |-----+-------------------------------------------------------------------------------------------------------( )----|
| | 5 | 3 |
| |DCS | |
| |ALARM | |
| |ACKNOWLEDG | |
| | N:P | |
| +----| |-----+ |
| 0 |
|*********************************************************************** |
|THE NEXT FIVE RUNGS COUNT RUN TIME IN HOURS AND ALLOW DC COUNTER RESET |
|*********************************************************************** |
|DN RUNNING |
|CLNR CONE |
|FEED PUMP RUN TIME |
| N:A T:I +--TON-----------+ |
52|----| |---------|/|----------------------------------------------------------------------------------|Timer On Delay |-(EN)-|
| 1 DN |Timer: T:I | |
| |Base (SEC): 1.0|-(DN) |
| |Preset: 60| |
| |Accum: 0| |
| +----------------+ |
| RUN TIME |
| MINUTE |
| COUNTER |
| T:I +--CTU------------+ |
53|----| |---------------------------------------------------------------------------------------------|Count Up |-(CU)-|
| DN |Counter: C:Q | |
| |Preset: 60|-(DN) |
| |Accum: 0| |
| +-----------------+ |
| RUN TIME |
| HOUR |
| COUNTER |
| C:Q +--CTU------------+ |
54|----| |------------------------------------------------------------------------------------------+|Count Up |-(CU)-+-|
| DN ||Counter: C:R | | |
| ||Preset: 32000|-(DN) | |
| ||Accum: 0| | |
| |+-----------------+ | |
| |RUN TIME | |
| |MINUTE | |
| |COUNTER | |
| | C:Q | |
| +---[RES]-----------------+ |
| RUN TIME |
| DAY |
| COUNTER |
| C:R +--CTU------------+ |
55|---| |----[AFI]----------------------------------------------------------------------------------+|Count Up |-(CU)-+-|
| DN ||Counter: C:S | | |
| ||Preset: 32000|-(DN) | |
| ||Accum: 0| | |
| |+-----------------+ | |
| |RUN TIME | |
| |HOUR | |
| |COUNTER | |
| |22-PP-010 | |
| | C:R | |
| +---[RES]-----------------+ |
|RESET CNTR |
|CLNR CONE RESET |
|FEED ONE RUN TIME |
|PUMP SHOT TIMER |
| N:E BF T:I |
56|----| |--------[ONS]-------------------------------------------------------------------------------------------+---[RES]---+-|
| 3 226 | | |
| |RUN TIME | |
| |MINUTE | |
| |COUNTER | |
| | C:Q | |
| |---[RES]---| |
| |RUN TIME | |
| |HOUR | |
| |COUNTER | |
| | C:R | |
| |---[RES]---| |
| |RUN TIME | |
| |DAY | |
| |COUNTER | |
| | C:S | |
| +---[RES]---+ |
Back to Main