Keysight E6640A, Measurement Applications User & Programmer Reference

Page: 142 / 2870

3 Programming the Test Set
STATus Subsystem
event register is cleared. Querying the event register allows you to detect that this condition occurred even
if the condition no longer exists. The event register can only be cleared by querying it or sending the *CLS
command.
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Monitor a particular type of change in a condition (bit).
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The transition registers are preset to register if the condition goes from 0 to 1 (false to true, or a
positive transition).
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This can be changed so the selected condition is detected if the bit goes from 1 to 0 (true to false, or a
negative transition).
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It can also be set for both types of transitions occurring.
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Or it can be set for neither transition. If both transition registers are set to 0 for a particular bit position,
that bit will not be set in the event register for either type of change.
Using a Status Register
Each bit in a register is represented by a numerical value based on its location. See figure below. This
number is sent with the command to enable a particular bit. If you want to enable more than one bit, you
would send the sum of all the bits that you want to monitor.
Figure: Status Register Bit Values
Bit 15 is not used to report status.
Example 1:
1. To enable bit 0 and bit 6 of standard event status register, you would send the command *ESE 65
because 1 + 64 = 65.
2. The results of a query are evaluated in a similar way. If the *STB? command returns a decimal value of
140, (140 = 128 + 8 + 4) then bit 7 is true, bit 3 is true and bit 2 is true.
Example 2:
1. Suppose you want to know if an Auto-trigger Timeout occurs, but you only cared about that specific
condition. So you would want to know what was happening with bit 10 in the Status Questionable
Integrity register, and not about any other bits.
142 W-CDMA & HSPA Measurement Applications Reference