remember last state

hi
can you help me to choose cheap plc that can remember the last state before switch it off or power failer
our application is to control the sequence of three pumbs two in operation one is stop for fixed time that after 24 houer the three pumps work for same no of operation houers even if power failer hapen or if switched plc off during that time
thanks

pretty much all PLC's have this capability either thru a latch instruction or in Omron its Set and reset other languages have their own instructions

Like said above most plc's have retentative memory.
if like the old S5 siemens where only part of the memory is retentative then you could copy say M bits to a DB every scan this will save most last states, however it would make sense to hold all processes & outputs until a start or re-start is made by the operator as a power on could cause a problem.
I have done this in the past by copying non retentative memory into DB's then on startup set a hold bit & restore the data from retentative memory (this was useful in S5 as databits could not be documented with symbols however in S7 you can.