2201R Mobile Tester SCPI Reference Guide
Chapter 2 Remote control of the 2201R Mobile Tester
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The figure below gives an example of a group of registers.
A group of registers starts with a Condition register. An internal Event sets the corresponding bit of the Condition
register (to 'set a bit' means a transition from binary
0
to a binary
1
). Any Condition register is updated continuously.
This means that a bit is reset as soon as the condition which raised that bit is no longer valid.
Example:
As soon as the 2201R starts to page a mobile under test, a certain bit of a certain condition register is set. When the
2201R stops paging the mobile (because, for example, it responded to the paging requests), this bit is reset. Now there
is no evidence for a paging process in this Condition register.
Therefore, an
Event
register is included in every group of registers. In the Event register, a bit remains set even when
the condition for it to be set is no longer valid. Any Event register, however, is cleared after a query.
Example:
Continuing our example from above, in the related Event register, the corresponding bit would still be set. A query of
this register would provide evidence that there has been some paging in progress. However, the Event register is not
able to provide any information if the condition is still valid.
Summary 1: condition-type versus event-type registers
•
The condition-type registers reflects the current status of the test set and is updated continuously. When you
would like to know if a special condition is currently valid, then read out the related condition-type register with
a query.
•
The condition-type register and the event-type register have an identical structure. This means that they are of
the same length and the single indicator bits are at the same positions.
•
The event-type registers are the 'memory' of the status system. Once a bit has been set, it remains set until the
event-type register is read out with a query. When you want to trigger (for example) your program with a certain
event, always read out the related event-type register.
•
Event-type registers are read-only and self-destructive. They are cleared after any query.
Transition of a bit from the condition-type to the event-type register
How does a bit find its way to the Event register?
This depends on the transition filter and its settings. The transition filter works as follows:
First, there are two branches: the Positive TRansition and the Negative TRansition filter. Both only react on the
corresponding transitions of bits and both contain as many bit positions as the condition register.
PTR carries a binary 1 at a bit position only when the corresponding bit of the condition register is set, while NTR
carries a binary 1 at a bit position only when the corresponding bit of the condition register is reset.
Both the outputs of PTR and NTR are combined with the corresponding mask, using a logical AND operation.
These masks are user-definable (using the
STAT:xxxx:xTR
commands) and again contain as many bit positions
as the condition register.
Example:
The only chance for bit 4 (that has just been set in the condition register) to reach the Event register is that the PTR
mask carries a binary
1
at bit position 4.
The logical AND between the PTR filter and the PTR mask then delivers a binary
1
. This binary
1
passes the logical OR
and thus sets bit 4 of the Event register.