Block Connectability; Active Blocks And Push/Pull - Sutron Xpert2 Operation And Maintenance Manual

We can now clearly see the inputs and outputs each block has available along with which are
being used and which aren't. It is now evident, for example, that only the pressure from the BP
block is being sampled (not the temperature) and that only the maximum value of this pressure is
being logged.

Block Connectability

The graphical setup allows any two blocks to be connected together as long as the first has an
output and the second an input. However, this does not necessarily mean that any constructed
setup will work. For example, even though the system will allow a sensor block to be hooked
directly to a log block, no data will necessarily be logged, unless there is an "active" block to
control when processing takes place ( "active" blocks are those with darkened borders; see the
example in the next section).

Active Blocks and Push/Pull

"Active blocks" are blocks that make the other blocks connected to them execute (or perform
their function). This results in data being pushed and pulled from and into the other blocks.
Active blocks always have a darker, thicker border, so they are easier to recognize.
Active blocks typically ignore the call to execute and push/pulls from other active blocks. This
helps to ensure the system is as determinant as it can be (i.e., this helps to ensure you can figure
out who's going to execute, and when).
In the example below, the first Measure block signals the Const block to execute, and then
pushes the result into the second Measure block and the lower Log block, L2. The data is logged
to L2, but since Measure blocks are active and thus ignore pushes and pulls, the data is not
logged to L3.
When the second Measure block executes, it signals the first Measure block to execute, and then
pushes the result to L3. When the Measure block is signaled, he simply returns the last known
value for Const, instead of measuring anew, again since active blocks ignore push/pull requests.
80
Bringing the Benefits of Real-Time Data Collection to the World
Sutron Corporation, Tel: 703-406-2800, http://www.sutron.com