Is there any autoguarding facility available in QT200? If so, how to use it?

This feature is available in QT200 and is very user friendly. We have explained about it below in detail. Kindly go through this and try to simulate it by yourself. If found any problem come back to us through the Customer Support form provided.
In QT200 Workstation Board Learn, consider that user has created a board with five devices as shown below.

U1 - 7400   - (Quad 2-input NAND gates).
U2 - 74245 - (Octal Bi-directional buffers with tri-state Outputs).
U3 - 74245 - (Octal Bi-directional buffers with tri-state Outputs).
U4 - 74245 - (Octal Bi-directional buffers with tri-state Outputs).
U5 - 7400   - (Quad 2-input NAND gates).

Among the five devices shown above only U2, U3, U4 are bus devices and the rest are simple gated logic devices. Let us consider U2 and U4 are using the common bus.

After entering all the devices learning the device U1, user will find device U2 on the learn window. Now press "Guarding" button which is shown below the "Learn" button. After clicking on "Guarding" button a guarding guide window appears as shown below.

• If the user has design documents related to this board, and he/she comes to know that only U2 and U4 are on the same bus and so U3 can be deleted. To delete U3, select U3 and click the "Delete" button. If in case user has deleted a device by mistake he can add them back to the guarding guide list by clicking on "Add" button.
• If the user is not aware of the circuit detail of the board, he/she needs to trace the links between the DUT and all other devices shown in the guarding guide. To trace the links between U2 ( DUT ) and U3, select U3 and click "Trace" button. Now the user will enter into trace links wizard which is same as Circuit Tracer but traces links only between the Bus pins and the enable pins.
• Steps on how to use Trace links wizard.

1) When the user clicks on "Trace" button, s/w enters into trace links wizard and "Clip definition" window is shown for the user to select the no. of pins for clip1 and clip2 and their starting channels.
For e.g. have a look at the clips defined below to trace the links between U2 and U3.

This clip definition window is shown to the user by default only when user is entering into this trace links wizard for the first time in this board. For rest of the time if user wants to redefine the clips he/she has to click at the menu "Utilities -> Define clips".

2) Place the clip1 on the DUT (U2) and clip2 on U3.

3) Click on the "Trace" button.

If any links are found between the two devices, they are shown on the screen else HZ is shown on all the Bus and Enable pins.

4) After tracing the links, Click the "back" menu / icon. You will come back to Guarding guide.

5) Repeat the same steps by selecting U4.

After tracing the links between the DUT and rest of the devices i.e. between U2 & U3 and U2 & U4 in this board, updated guarding guide will appear as shown below.

From the updated guarding guide delete the devices whose remarks are shown as "Traced, not on the same bus" to avoid confusions.

6) Click on OK button for the information to get updated.

• User needs to repeat the whole process to trace the links between rest of the combination.
• After tracing the links between all the Bus devices in a board, user can start learning them.

While Learning / Testing any bus device, updated guarding guide is shown. Now user need to make use of flying channels and follow the instructions as shown in the guarding guide.

For e.g. while learning U2, set any flying channel to "High" and connect them to pin # 19 of U4.

In case you want some more information regarding this or on any other like problems you can mail your queries using the form below.

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