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WorksheetsUnit 13 A plc revision
Total questions: 6
Worksheet time: 16mins
Convert the binary number 10111101 to decimal
174
189
157
182
Convert the decimal number 146 to binary
10010001
10010011
10010010
1001100
Convert the decimal number 124 to hexadecimal
18
9
6c
7c
The majority of PLCs work using the refresh or batch process mode. This involves the PLC in a continuously repeating scan cycle of copying the status of all inputs to memory, working through the stored program and then updating the outputs. Give TWO significant limitations of this process:
How many binary bits are needed to store the BCD number 1375?
1=001
3=011
7=111
5=101
16bit
1=0001
3=0011
7=0111
5=0101
16bit
1=0011
3=0001
7=0111
5=0101
8bit
1=0001
3=0011
7=111
5=101
8bit
A PLC system has an input filter delay of 5ms, relay outputs with a quoted delay of 8ms and, when monitored, the program scan times are 12ms minimum and 32ms maximum. For a given input change calculate the best case AND worst case response for an output directly controlled by that input: Marks
Min = 24ms
Max = 78ms
Min = 25ms
Max = 29ms
Min = 25ms
Max = 77ms
Min = 26
Max = 82
