temperature is being maintained if the rinse water is not at the proper temperature the controller 37 adds the sanitizer chemical from the dispensing system 20 a pair of sensor switches dr 74 provide signals indicating when either side door 14 is open and the controller 37 suspends operation in those cases a set of three sensors 75 76 and 77 respectively detect when the chemical containers 22 23 and 24 are empty the present invention relates to a mechanism which dispenses chemicals from the dispenser 21 based on the information read from the data recorded on the containers 22 24 placed into the dispenser occasionally the microcomputer 38 reads the data signals from the three data readers 33 35 to determine characteristics of the chemical at each dispenser port 26 28 in the preferred embodiment the data readers are polled each time a washing operation commences however in other cases the signals from the data readers may be inspected by the microcomputer 38 whenever the operator changes a chemical container and presses a button on the dispenser 21 to indicate that event in a system in which each dispenser port 26 28 has a reservoir that holds the chemical received from a container the data reader scans the indicia when an operator fills the reservoir from the container when it is desired to read the signals from the three data readers 33 34 and 35 the microcomputer 38 executes a software routine 100 depicted in fig7 that routine commences at step 102 by setting a variable designated a port pointer to one to indicate the first port 26 of the dispenser 21 then at step 104 the microcomputer reads the signal from the data reader for the indicated port.