F5HO12 Applications of PLC Tutorial
Please answer all the questions in your own words.
You may use Microsoft word or take a picture of your working and paste it
into this document.
1. Describe in your own words how continuous updating works and what
type of PLC it is suited to?
A CTU (microprocessor) scans a number of input contacts as called for
In a sequence of instructions this may vary depending on instruction.
An outport is then directly driven on instructions following logical out
Instructions.
Outputs are latched until the following scan cycle begins, an input scanner uses software ( built in delay) this prevents contact
bounce which makes the input state read.
This method is only used for Small PLC’s due to timing sequences.
2. Describe in your own words how Mass Input/Output Copying works and
what type of PLC it is suited to?
Mass I/O copying works by scanning inputs and facsimile to RAM. Fetch and decode followed by executing of all program
instructions of sequence of copying output facsimile to RAM. Once all the program has been processed a CPU will use
diagnostics and communications. Will update all outputs and then cycle will repeat.
Mass I/O Is used by companies such as Tennets Larger for example there bottling plant produces 100,000 cans of larger per hour
a continuous update PLC could not handle the demand there fore a Mass plc system must be used. This is due to the timing
sequence.
Please answer all the questions in your own words.
You may use Microsoft word or take a picture of your working and paste it
into this document.
1. Describe in your own words how continuous updating works and what
type of PLC it is suited to?
A CTU (microprocessor) scans a number of input contacts as called for
In a sequence of instructions this may vary depending on instruction.
An outport is then directly driven on instructions following logical out
Instructions.
Outputs are latched until the following scan cycle begins, an input scanner uses software ( built in delay) this prevents contact
bounce which makes the input state read.
This method is only used for Small PLC’s due to timing sequences.
2. Describe in your own words how Mass Input/Output Copying works and
what type of PLC it is suited to?
Mass I/O copying works by scanning inputs and facsimile to RAM. Fetch and decode followed by executing of all program
instructions of sequence of copying output facsimile to RAM. Once all the program has been processed a CPU will use
diagnostics and communications. Will update all outputs and then cycle will repeat.
Mass I/O Is used by companies such as Tennets Larger for example there bottling plant produces 100,000 cans of larger per hour
a continuous update PLC could not handle the demand there fore a Mass plc system must be used. This is due to the timing
sequence.
