Danfoss MCO 305 Design Manual page 117

MCO 305 Design Guide
Oscilloscope Versions
There are four versions of the Oscilloscope available to users. Each version is designed for a different use
but all versions basically operate in a similar manner and have a similar appearance. The Free Run, Single
Shot, and TESTSETP Oscilloscopes are designed for debugging and diagnostics. The Tune Oscilloscope is
designed for optimizing system performance.
Free Run Oscilloscope
The Free Run Oscilloscope is a tool designed specifically for diagnosing operational problems in running
systems. However, it can also be used for debugging prototype applications. It is referred to as "Free Run"
because the application on the controller can run freely without regard to how the Oscilloscope is being used
or that it is being used at all. The impact of the existence and usage of the Oscilloscope on the running
application has been minimized as much as possible. This allows the controller to behave as it would in
actual operational situations.
Values are recorded and displayed in real time during the actual test. This information is normally collected
using PDO messages from the controller.
NB!:
Note that PDO messages are not supported by some older controllers and by some connection
interface types.
Free Run Oscilloscope in Polling Mode
In certain circumstances, the user may be unable or unwilling to allow the Oscilloscope to use PDO
messages. Reasons for this include the following:
− The running application may already be using all available PDO message types. In this case, there will
be no free PDO message type that the Oscilloscope can use to receive curve data from the controller.
− The controller may have an older version of firmware installed that does not support the dynamic
configuration of PDO messages. The Oscilloscope will then be unable to configure the required PDO
messages.
− The controller may be connected using a connection interface type that does not support PDO
messages.
In these cases, the Free Run Oscilloscope either cannot be used or must be used in the slower "polling"
mode. Note that using polling can have a significant impact on the performance and response of the
controller and the communication network.
If the Free Run Oscilloscope cannot be used, then it may be possible to use the Single Shot Oscilloscope as
an alternative.
Single Shot Oscilloscope
The Single Shot Oscilloscope is designed more for debugging prototype applications than it is for diagnosing
operational problems in running systems. However, it can be used for both. It can also be used in some
situations where the Free Run Oscilloscope cannot be used.
It is referred to as "Single Shot" because the curve data is recorded on the controller itself and then
uploaded to the Oscilloscope after the test is complete.
Values are recorded on the controller in a TESTSETP array. The allocation of this array can be done either
manually by the user (i.e. by defining a user array for the purpose) or automatically using available free
memory in the controller. In either case, the Single Shot Oscilloscope may affect the memory management
of the application program. The TESTSETP array will be automatically configured by the Single Shot
Oscilloscope when recording begins.
NB!:
Some older controllers do not support the automatic configuration of TESTSETP arrays. In these cases,
the Single Shot Oscilloscope cannot be used; the TESTSETP Oscilloscope should be used instead.
__ APOSS Tools __
®
MG.33.L5.02 – VLT is a registered Danfoss trademark
117