Qld Contact Types

The following types of contacts are available in Quick Ladder.

Direct Contact Example

The following can be used to demonstrate a direct contact. Whenever #18.31 is set, #18.32 is set. When #18.31 is clear, #18.32 is cleared.

Inverted Contact Example

The following can be used to demonstrate a direct contact. Whenever #18.31 is set, #18.32 is cleared. When #18.31 is clear, #18.32 is set.

Positive Edge Contact Example

The following can be used to demonstrate a positive edge contact. Before executing the example on a target, ensure that the values of parameters #18.31, #18.32 and #18.21 are 0.

Execute the example. Set #18.31 to 1. #18.32 will be momentarily set and #18.21 will be set to 100. It is unlikely that SYPT will show #18.32 change value since on the next scan through the diagram, #18.32 will be cleared. This will happen too quickly for SYPT to detect. However the second rung moves 100 into #18.21 if #18.32 is set. This shows that #18.32 was set.

Negative Edge Contact Example

The following can be used to demonstrate a negative contact. Before executing the example on a target, ensure that the values of parameters #18.31, #18.32 and #18.21 are initially 0.

Execute the example. Set #18.31 to 1. No parameter values will change. Now set #18.31 to 0, #18.32 will be momentarily set and #18.21 will be set to 100. It is unlikely that SYPT will show #18.32 change value since on the next scan through the diagram, #18.32 will be cleared. This will happen too quickly for SYPT to detect. However the second rung moves 100 into #18.21 if #18.32 is set. This shows that #18.32 was set.

See Also

• QLD (Quick Ladder Diagram) Reference

• QLD Elements

• QLD Coil Types

________________________________________________________________________________

Advanced Position Controller

UD7X, SM-Applications and SM-Applications Lite include embedded, multifunction motion kernels. The kernels provide a wide range of features including (dependent on the target):

1. Stop

2. Position Reference

3. Speed Reference

4. CAM

5. Digital Lock

Detailed information on the features and usage of the Advanced Position Controllers can be found in the UD70 manual and the APC User Guide both of which are available from the Help menu in the DPL editor.

See Also

• Advanced Position Controller

________________________________________________________________________________

Programming Hints and Tips

The following tips provide information on improving the performance and maintainability of user programs.

Avoid Floating-Point Mathematics

Floating-point mathematics (+, -, * and /) is very slow compared to integer mathematics.

If performance is an issue use integer variables. To represent decimal places, use fixed-point arithmetic. For example, if a resolution of .001 is requires, let 1=1000. This allows the accuracy to be maintained throughout mathematical operations.

On the SM-Applications and SM-Applications Lite modules compiling for the single-precision model ($FLT SINGLE) can provide a small increase in performance over the default double-precision floating-point model. Single-precision mathematics is still much slower than integer.

Minimise Parameter Access

Parameter access is slow compared to variable access. Minimise the number of times parameters are accessed. If a parameter value is need more than once in a single schedule of a task, read the parameter value into a temporary variable. The access time of a parameter can be up to 50 times slower than the time taken to access a variable.

Use Names as Aliases for Parameter Numbers

Using the $DEFINE command, a name can be used to represent a parameter number or a constant value. This gives the benefit of making a DPL program easier to read, work with and change at a later date. Note that it does not give any program execution speed benefit.

It is recommended that alias names are in upper-case letters so that they can be more easily distinguished from variable names.

Example

Note:

When creating an alias to represent a integer value or parameter, use a `%' sign after the alias name. This will allow the alias to be used in Ladder and Function Block diagrams.

________________________________________________________________________________

Glossary

The glossary defines terms used in SYPT. To optimize your search for a definition, click one of the following letter groups

A-C

D-K

L-M

P-W