Select this tool if you want to place additional retentive or time-related function blocks on the programming interface. LOGO!Soft Comfort then displays a toolbar of special function icons:
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The LAD Editor offers you the following additional functions: |
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FBD and UDF Editors: description of the blocks of special functions |
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The LOGO! version you have selected determines these characteristics of your circuit program:
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This topic also describes the following tasks or characteristics of the special functions:
Inverting inputs
Block configuration
Reference parameters
Protection
Retentivity
Inverting inputs
You can invert individual inputs:
You can invert a logical "1" at a specific input to logical "0" in the circuit program.
You can invert a logical "0" to logical "1" in the circuit program.
To do so, right-click the input and select the invert command from the shortcut menu.
You cannot invert the inputs of output blocks.
Note
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0BA0-0BA3: To invert an input, use the basic function NOT |
Block configuration
The block properties dialog provides you with an easy means of setting the various block parameters.
Reference functionality
You can also assign parameters to blocks with the value from other blocks. Such parameters are reference parameters.
The parameter box displays the block's parameters in a table. You can reference any parameter in the parameter box to the parameter of another function. You can use the show/hide button to change the visibility of the parameter box.
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① |
Show/hide button |
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② |
Output connector |
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③ |
Input connector |
Each parameter has an input connector and/or an output connector. You can simply use drag and drop to create a reference line between the parameter connector of one function and the parameter connector of another function. Note that you cannot connect output parameters to other output parameters.
The reference line between two parameters indicates their reference relation. You can delete the reference line to remove the reference.
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LAD Editor/0BA4-0BA7: The parameter box is not available in the LAD Editor or for 0BA4-0BA7 devices. Follow the below steps to create a reference:
For example, if you click the "Reference" button for the Off-Delay parameter of an Off-Delay timer, you can then choose a specific block to reuse the time value of that timer. |
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LOGO! 0BA7 and LOGO! 0BA8 devices provide a timer reference function. With this function, you can take the current time (Ta) of a timer as the reference value (C) in other function blocks. The calculation of the reference value (C) follows the formula as shown below:
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Current time (Ta) |
Time base |
Reference value (C) |
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A : B |
Hours (h : m) |
C = A × 60 + B |
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A : B |
Minutes (m : s) |
C = A × 60 + B |
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A : B |
Seconds (s: 1/100s) |
C = A × 100 + B |
Protection
If a Protection Active check box exists for the protection of a block parameter, you can enable or lock the display and editing of this parameter in LOGO! configuration mode.
Retentivity
The switching state and counter values of SFBs can be retentive. This means that the current data values are retained, for example after a power failure, so that the function is resumed at the break position after power on. Hence, a timer is not reset, but instead the time-to-go expires.
You must set the retentivity to enable this feature for the relevant function. There are two possible settings:
On: Current data values are retained.
Off: Current data values are not retained (default).
The Hours counter is an exception, because it is always retentive.