Part 2

592 Example 3497A ConfigurationsEXAMPLE 9COUNT UPIDOWN MEASUREMENTSDESCRIPTIONThe 100 kHz Reciprocal Counter assembly (Option 060) can be used for two primaryfunctions: counting operations (count upldown) and periodlpulse width measurementsof input signals. In this example, we'll show how to use the counter assembly tocount down a number of input pulses of an oscillator and how to count up (totalize)input pulses from a measurement system.PROCEDURETo illustrate the count up procedure, we'll totalize the number of input signals fromthe circuit in Figure 196 (a) for 5 seconds and print the results. In this circuit, a pulseis input whenever the conveyer belt interrupts the light source. By totalizing thenumber of counts in 5 seconds, we can (for example) determine if the conveyer beltspeed is correct.To illustrate count down, we'll preset the counter to 5000 counts, input a 1 kHzsignal from an oscillator as shown in Figure 196 (b) and, after a 2 second wait, printthe counts remaining. Since the period of a 1 kHz signal is 1 msec, after 2 seconds2000 pulses should have been input to the counter and 3000 counts should be remaining.We can then use the remaining counts to determine actual oscillatorfrequency.CONFIGURAT IONFigure 196 shows hov v to configure the Option 060 assembly using Isolated Inputmodeso that an external pullup is not required.SAMPLE PROGRAMSA sample COUNT UP program for an assembly in slot 4 is shown which starts countingup at t=O. After a 5 second delay to allow about 5000 counts to accumulatein the counter, data is transferred to the controller by the CR4,l command and theactual number of counts printed out.Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com