program advice

[MEK]

imagine that I have 4 pumps and I try to run them in sequence for instance when I take a start input the plc will start the last stop one and when I take the stop input the plc will stop the first start one. If you can give me some idea about this logic ,I will be pleased. Thanks

[sathya]

hello sir, sorry i'm unabel to understand ur question, plz be in points

[Ken Moore]

I THINK he wants to start 4 pumps in sequencial order. When the start command is received the first time, pump 1 runs, next time pump 2, etc... Then when the stop command is received, the pumps stop in the same order pump 1 stops first, then pump 2, then pump 3, finally pump 4.

[Groo]

If thats the case then how about one out of a million solutions // Create Start/Stop One Shot Triggers A "Start" FP "Start Pos Edge" = "Start Trigger" A "Stop" FP "Stop Pos Edge" = "Stop Trigger" AN "Start Trigger" // If not Starting Jump to Stop JC stop A "Run Pump 1" A "Run Pump 2" A "Run Pump 3" S "Run Pump 4" // Run Pump 4 Last A "Run Pump 1" A "Run Pump 2" S "Run Pump 3" // Run Pump 3 Third A "Run Pump 1" S "Run Pump 2" // Run Pump 2 Second SET S "Run Pump 1" // Run Pump 1 from Initial Start stop: AN "Stop Trigger" // If not Stopping A "Safety OK" // AND Safety systems are OK JC pump // Jump to Output Control AN "Run Pump 1" AN "Run Pump 2" AN "Run Pump 3" ON "Safety OK" R "Run Pump 4" // Stop Pump 4 Last / Immediate if Safety Failed AN "Run Pump 1" AN "Run Pump 2" ON "Safety OK" R "Run Pump 3" // Stop Pump 3 Third / Immediate if Safety Failed AN "Run Pump 1" ON "Safety OK" R "Run Pump 2" // Stop Pump 2 Second / Immediate if Safety Failed SET R "Run Pump 1" // Stop Pump 1 from Initial Stop // Output Control pump: A "Run Pump 1" = "Pump 1 Output" A "Run Pump 2" = "Pump 2 Output" A "Run Pump 3" = "Pump 3 Output" A "Run Pump 4" = "Pump 4 Output" The basics of one anyway....

[sathya]

hello sir, is there any time gap b/w the start of each pump and stop of each. regards sathya

[Groo]

I presumed he wanted to start each with the same button, it would be quite easy to change to a timer and counter and use the count values to start/stop. Did anyone notice my deliberate ,mistakes (cough) the stop should be AN not A and the stopping is done in the incorrect order if Mr Moores assumptions are correct .. ah well we're not always perfect. Edited May 15, 2006 by Groo

[sathya]

I presumed he wanted to start each with the same button, it would be quite easy to change to a timer and counter and use the count values to start/stop. Did anyone notice my deliberate ,mistakes (cough) the stop should be AN not A and the stopping is done in the incorrect order if Mr Moores assumptions are correct .. ah well we're not always perfect.

[MEK]

sorry for being so late to answer your questions yes you did very well about the understanding of program. we are usin one start and one stop .for instance we had a start signal firstly the pump 1 will run and in the case of having a new start signal the pump 2 will run with pump1 and so on. And if we have any stop signal then the first runned pump will stop and so on tanks