Schematic Capture
 

Q1:

How can I make my working sheet large enough to draw a big schematic?

Q2:

How can I stop the Bus member number sliding, when I delete a net, that is bus connected with a defined bus number? I wish that the other nets in bus hold their previously defined bus member numbers.

Q3:

In Schematic capture, after a circuit is drawn , we autopackage Can you explain what is actually taking place in autopackaging and why ?

Q4:

Why do we need to specify the swap level in the entry attributes? What difference it is going to make if it is given 1 or -1? And why do we need visible pinout?

Q5:

I autopacked a schematic and all four opamps went into four separate IC's. Then on trying to get them into one IC, I find that I cannot individually pack the op amps. How do I sort this out?

Q6:

EDWin32 concept of nets and wires

Q7:

How do you print the schematic hierarchy contents?

Q8:

How can you assign default pin number for schematic in edit part?

Q9:

How do you change the thickness of wires?

Q10:

When I use "redraw on component" in Schematic, an error-message "component not found" appears although the component is apparently there in the schematic and in the printout.

Q11:

How can I make Pin numbers of a new symbol visible in different Editors?

Q12:

About Merging and Splitting of Nets: I am not able to split and also end up in merging the nets which I don't want to?

Q13:

How is a resistor, capacitor, inductance etc. given a value and a power rating in schematic capture. In the file -res.part, what does rc5a, res15w, rn50, rsip5 etc. mean in terms of component, value, power rating etc.?

Q14:

I made the schematic diagrams and the layouts for an audio pre-amplifier and amplifier in 2 different databases. Is it possible to merge the two merge both diagrams and layouts to create one single schematic diagram and layout?



Q1: How can I make my working sheet large enough to draw a big schematic?

You can redefine the page size using the function tool "Define page outline as rectangle" from Edit/Page format menu item. Select this function tool and click on the graphics area. You will get a window where the new page size may be selected. Otherwise you may draw the rest of your schematic in a new page.



Q2: How can I stop the Bus member number sliding, when I delete a net, that is bus connected with a defined bus number? I wish that the other nets in bus hold their previously defined bus member numbers.

If you are deleting the whole net by selecting the function tool "Delete whole net", then on redrawing the circuit the bus member number also gets renumbered. This is because on deleting a net, the part once again gets repacked and it renumbers the bus members also.

More on Bus member number

Bus member number allows to group nets having the same bus member number, So it is advisable to have default numbers (0,1,2...). If the default bus member number (e.g. 0) is to be changed, then select Recover net/ Bus labels and click on the bus member number. In the window, enter the required name (D0) and click O.K.. Now click on all the bus member number having the same bus member number (0) and assign D0.

On the other hand, if the Net name (NET1) is to be changed , then select Edit Nets function tool in the Edit/Nets mode and click on the net name. In the pop up window, change the name (NEW NET1). Now you will find that all the net having the same net name (NET1) will be changed to the new name (NEW NET1).

Related topics

Recover Net/bus label text

Purpose: This option allows to Recover Net/ Bus label text & Bus member number and also allows to edit Bus name, Bus member number and Net name.

Operation:

To recover

Net name click on the wire nearer to the node. Bus member number: click on the wire nearer to the bus. Bus name: click on the bus.

The recovered text get tagged to the cursor. Now place this text just below the wire from where it is recovered inorder to avoid confusion.

To edit

Net name:Click on the net name and enter the new name in the window that opens. This method of change is not advisable because all the nets having the same name should also be changed to the new name.

Inorder to avoid confusion net name may be changed by using the tool Rename existing net or text edit new net invoked from Edit/Nets which changes all the nets having the same name, then the net name may be recovered using Recover Net/ Bus label text tool.

Bus member number: Since this number allows to group nets having the same bus member number, it is advisable to have default numbers(0,1,2...). If the default bus member number(e.g. 0) is to be changed, select Recover net/ Bus label and click on the bus member number. In the window, enter the required name(D0) and click O.K.. Now click on all the bus member number having the same bus member number(0) and assign D0.

Bus Name: Click on the Bus name and edit it in the window that pops up OR Select the option tool Rename bus and click on the BUS.

The ability to add board description notes to any layer was removed on purpose. This again will create problems when generating Gerber files. It is for this purpose that we have introduced Mechanical plot. This contains mechanical details of the file such as dimensions and notes that are available on Comp. Print and Solder Print.

Rename Existing Net Or Text Edit New Net

Purpose:

While preparing the schematic diagram, a net may not be named according to its functionality. Later it may be required to rename the net according to the function it performs. This function tool may be used to rename an existing net.

Operation:

Select this function tool and click on the net to be renamed. A dialog box listing the nodes and the present name of the net gets displayed. The name may be changed in the text box Netname and to confirm the change click the "ACCEPT" button.

To recover the new net name select Recover net/bus label text function tool from Edit-> Traces.



Q3: In Schematic capture, after a circuit is drawn , we autopackage Can you explain what is actually taking place in autopackaging and why ?

The autopackaging utility allows to perform the automatic packaging of all unpacked components and it assigns the first free number to the last placed components belonging to the same group. The component Name prefixes from Part descriptions are used to automatically generate component names.

When you actually autopackage, system extracts the package assigned to the part at the time of creation. This is how it displays the respective package facilitating front annotation.



Q4: Why do we need to specify the swap level in the entry attributes? What difference it is going to make if it is given 1 or -1? And why do we need visible pinout?

If Swap Level is set to -1, it will not allow the pin to be swapped. If it is set to 1 or any positive integer, this means that the pin can be swapped with any other pin having the same swap level. For e.g.: the input pins of 2NAND may have their swap level set to 1 since they may be swapped. But the output pin of 2NAND should have this swap level set to -1. If you want view pinout after packaging, you can set the Visible Pinout option i.e. it decides whether pinout should be displayed when packaging.



Q5: I autopacked a schematic and all four opamps went into four separate IC's. Then on trying to get them into one IC, I find that I cannot individually pack the op amps. How do I sort this out?

This could have happened in the following way:
For e.g.: LF147 contains four symbols OPAMP, OPAMPA, OPAMPA, OPAMPA. To load the part LF147, Select the function Create Component to open the Create Component window. In this window under part text box, LF147 will be displayed and in the symbol text box OPAMP is displayed. When ACCEPT is clicked OPAMP is loaded. If this step is repeated again, another OPAMP symbol will be loaded. Now packaging the symbols will load two ICs of part LF147 in the layout. This is because part LF147 contains only 1 OPAMP. On the other hand, if you select OPAMPA from the symbol dropdown list while loading the part LF147, and then package, you will get only one IC in the layout since a single LF147 contains OPAMP and OPAMPA.

The function tool Repack allows repackaging an already packaged component. Packaging of a component is done according to the setting in the EDWin32 Main Menu Options/Packaging Preferences. The three settings in the Preferences for packaging are Component name, Description and Pinout details. Any or all of these can be set or removed. If you select a packaged component, change the default settings of Packaging Preferences and try to package it again, an error message appears saying "This component is already packaged". So to package the component with the new details use Repackaging option.



Q6: EDWin32 concept of nets and wires

Net is a collection of nodes that are electrically connected together. A wire is merely a visual representation of the corresponding net description. The creation of a wire automatically results in the creation of the corresponding Net. Further, the deletion of a wire removes only the wire but does not remove the Net whereas the deletion of a net removes ALL the associated wires. The deletion of a node in the net removes the corresponding connection in the net and removes the associated WIRE SEGMENT also.

It is possible to delete a wire and the corresponding net connection together by the following procedure. From the Schematics Capture window select Edit/ Nets. Select the 'Delete single Node' tool (shortcut *NN) from the vertical toolbar. Click on the appropriate node. A confirmation box pops up asking to confirm the delete operation. Select Yes to delete the node. This will delete the associated wire segment also.



Q7: How do you print the schematic hierarchy contents?

To print the Schematic hierarchies, select the specific Schematic hierarchy from the list of hierarchies and select Schematic Capture. Then Select Pages/Print Page to print the schematic hierarchies.



Q8: How can you assign default pin number for schematic in edit part?

You cannot assign default pin number for schematic in Edit Part. When a new entry is created default pin numbers will be set by the system in the order of creation i.e. the first (default) entry on screen will have pin number #1 assigned to it, the next one is given the number #2 and so on. This will be displayed on screen if the option View /Symbol/ Entry Number
.

Q9:How do you change the thickness of wires?

The thickness of wires & buses can be changed even after routing.

1. Invoke Options /Sizes /Conductors from EDWin32 Main. 2. In the text boxes provided for bus and wire line width, change the value to say .050.

Now to effect this change as default settings. Check Options-Default to current.
Note that if this change is just for the current database, then before changing the value, check Options-Current and proceed with the above two steps.

Q10: When I use "redraw on component" in Schematic, an error-message "component not found" appears although the component is apparently there in the schematic and in the printout.

When you redraw a component in Schematic, specify the group of the symbol on which the zooming operation is to be done, i.e. zoom on 7474/1 that is packaged as IC4 in the schematic. Enter the name as IC4/1 in the input box that pops up when "Redraw on Component" is selected. On the other hand when redraw on component is done in the Layout, only the name IC4 is to be entered. Select tool "Display Component Info" and click on any component in the schematic, the component name is given along with the symbol group. This is the way the names are to be given when redraw is done.



Q11: How can I make Pin numbers of a new symbol visible in different Editors?

Load the symbol and check PA Texts from View menu. Position the PA Text and select the "Edit Entry Attributes" tool. Now click on each entry and check the "Visible Pinout" check box. This will display the pin numbers in the Schematic after the component is packaged. Make all PA texts of a symbol visible/ invisible using Library Viewer as follows:

In Library Viewer, Edit the symbol. In the dialog that pops up, check "EDIT PA SHIFT " option button. Now click on any of the entries and click "ALL VISIBLE"/ "ALL INVISIBLE " button. Note that with both the methods it is necessary to save the symbol after editing. In Library Viewer the "EXIT" button will be enabled only after unselecting the entry by clicking in a vacant area. Also note that pin numbers may be made visible in schematic only if the component is loaded as part.



Q12: About Merging and Splitting of Nets: I am not able to split and also end up in merging the nets which I don't want to?

Splitting nets is a very simple process in EDWin32. Now say that you want to delete UN1. Delete a wire segment. In Edit/ Nets mode, Select Split Nets function tool. Click on the wire (UN1), the entire net gets selected. Click once again on the same wire, this pops up a window, enter a new net name (system automatically inserts the first free number) and check "Named " in the window. Accept the new net name and verify using the tool Display Net info. To merge, select the net you want to merge and click on the another net. A confirmation prompts. Now click YES to merge two nets into one.



Caution: Before Splitting of nets, ensure that a wire segment is deleted.

Q13: How is a resistor, capacitor, inductance etc. given a value and a power rating in schematic capture. In the file -res.part, what does rc5a, res15w, rn50, rsip5 etc. mean in terms of component, value, power rating etc.?

The resistor/capacitor library was created based on resistance values coded according to the MIL standard. The name of each resistor is formed by concatenating the IEC coded resistance value with the corresponding package name. The MIL notation for values is as follows:

In a 'N' digit value first (N-1) digits represent the significant figures and the last digit represent the number of zeros to follow. The position of 'R' denotes the decimal point.

For example 1001 -> 10000 (10K)
1002 -> 100000(100K)
2R7 -> 2.7
10R0 -> 10.0

That means the part 1000RC07 represents a 10K resistor using a RC07 layout. This was done so that the schematic displays the values correctly after packaging but on the other hand offered only a few layouts for the design. Now the resistor/capacitor library is restructured according to the standard Sizes and wattages are available and a different technique is designed for representing the values in the schematic. Also each part is attached with a "Full Name" that gives a short description.

In EDWin32 there is a feature to add component values in schematics. For this you have to select Edit /Components and select the function tool Add component text/Component value(shortcut. *CT). They will appear on diagrams and component list (list of materials editor).



Q14: I made the schematic diagrams and the layouts for an audio pre-amplifier and amplifier in 2 different databases. Is it possible to merge the two merge both diagrams and layouts to create one single schematic diagram and layout?

You cannot make any link between two databases in EDWin32. The only way is to Block copy one schematic into the other and paste it in the first database. And make necessary net connections to work properly. This process is relevant for the Layout Editor also.