Quantum Data 881, Руководство пользователя

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86 Chapter 12 CEC Interactive Troubleshooting Environment (ITE)
commands through the ACA. The bit timings are shown in the Details panel. Note in
the example below the logical 1 bit timing has been reduced.
L
Bus arbitration tests
You can test a device’s response to arbitration errors through the command line. There
are three arbitration tests that you can perform:
• Force a connected device to stop sending.
• Force a device’s address to 0 to cause a sending device to stop sending.
• Force a bit of a sending device to go low when it should not be. This results in a
corrupted bit and simulates a device accidently sending on the bus.
Bus arbitration tests involves sending a command to cause the device under test to try
and seize the bus while also seizing the bus by the emulated device. This simulates a
condition where two devices may start sending at the same time which means they try and
seize the bus at the same time. When the device under test detects that another device is
seizing the bus it should send a low signal (force the bus low) to indicate to other devices
(the device emulated by the 880) that it (the device under test) has detected an error.
To test bus arbitration conflicts through the command line:
1. Enter the following commands to simulate arbitration errors.
CEC1:CECT:ARBM 1 0 0 /forces a sending device connected to the
bus to stop sending