Chapter 8
SCPI
The communication-related subsystems
4460 GSM System Option and 4468 EDGE System Option
Version 12.20
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Summary 2: from the condition-type to the event-type registers
– There are two detectors for every bit of a condition register: the
positive
transition and the
negative
transition branch. Positive transition means a
change of a bit from a binary
0
to a binary
1
while a negative transition is a
bit change from a binary
1
to a
0
.
– To every branch, there is a filter mask (PTR and NTR mask). This filter mask is
user-definable.
– The filter mask and the result of the transition filter are combined using a
logical AND operation.
– The results of the AND operation in both branches will be combined, using a
logical OR operation.
– The results of the OR operation are the contents of the related event-type
register.
Moving up: an event reaches the condition register one hierarchical level up
The
Event register
contains summary bits, corresponding to the bits of the
condition register. A summary bit will be set, when the initial event passes the
transition filter.
The
Enable filter
is a mask to filter events that are allowed to move one level up.
The Enable filter is user-definable (using the
STAT:xxxx:ENABle
commands)
and again contains as many bit positions as the condition-type register.
Again, the Enable filter mask is ANDed with the Event register and a nonzero
result will finally set the
Result
bit. This Result bit may be a summary bit either
in a higher-level register, or in the service register.
Summary 3: raising the Result bit
– The event-type register will be ANDed with the related Enable filter mask.
– The Enable filter mask is user-definable.
– The result of the logical AND operation between event-type register and
related Enable filter will be the Result bit.
– The result bit will set the corresponding bit of the condition register one
level up.
At the top: the service register
The
service register
contains eight summary bits: three for the status groups
available on the 4400, two for internal queue handling, two for remote control
and one bit for it's own status: the
summary status bit
.
When an event passes through and sets one of the seven corresponding summary
bits of the service register, the contents of the service register will be ANDed with
the service register mask. This mask can be set using the
*SRE
common
command.
When the logical AND operation of the current contents of the service register
and the service register mask leads to a binary
1
, then the summary status bit
will be set as well.
