Remedy for Speed Ratio issue – Microlog dBX with @ptitude Analyst

Summary

This article describes how to resolve an issue where, incorrect speeds are shown in SKF Microlog Analyser dBX for fixed speed Machines/Points.

The SKF Microlog Analyzer dBX (CMVA 90) has a different way of handling Point speed ratios when compared to its predecessor (CMXA 75 and CMXA 80).

Under normal circumstances, this does not affect Route Point collection and is not apparent to the user.

There are two setups where point speed ratios come into effect:

1. When using speed tagging, a Point set up option in @ptitude Analyst where a Point references another point (a speed, process or other type of Point) and defines a speed ratio.
   On collection, the device obtains speed from the speed reference Point (also known as speed tagging) and applies the Point’s speed ratio to find the actual rotation speed at the Point’s location.
   
   
2. When not using speed tagging, each Point in @ptitude Analyst can have a default speed defined. When you want to see this speed on the device and in the collected data, the Microlog dBX takes this default speed, adds it to the measurements and shows it on the spectrum screen.

When using the second setup mentioned above (fixed speed Points without any speed reference), the speeds may be inaccurate on numerous Points. With no correlation between the speeds shown in Data Collector and most of the @ptitude Analyst Points’ setup.

In this setup, it is expected that the speed ratio in each Point, being fixed speed and not using speed tagging, would be 1.0. When programming the Route for download, TCT.dBX uses the speed of the first Point in the machine as a reference, and for any following points that have a different speed, it applies a speed ratio to factor the first Point’s speed to the one required. (The reason for this is that the CMVA 90 uses the parent machine to hold the speed).

The Route builder in TCT.dBX uses some checks to determine if it needs to handle this, one of which is requiring that the Point’s speed ratio equals one.

The problem occurs due to corruption or invalid values in the @ptitude Analyst database.
Many of the Points had speed ratio values not equal to one. In this Point configuration, you cannot see or edit this speed ratio value in the Point editor.

This led to the library not applying the correct speed ratio since the Point appeared to have one of its own.

Solution

A script which can correct these speed ratio problems is available. Please contact the SKF Technical Support Group (TSG) for guidelines.

Contacting SKF Technical Support Group

For further assistance please open a support case using the Technical Support group's self-help portal at www.skf.com/cm/tsg. Once your support case is submitted, a technician will contact you to begin working on your issue. For urgent issues we are available at these times by phone:

• Monday through Friday, 5:00 a.m. to 4 p.m. Pacific Time -
  Phone: [phone] within the US or [phone] outside the US.
• Monday through Friday, 8:00 a.m. to 4:00 p.m. Central European Time -
  Phone: [phone].
• Monday through Friday, 7:30 a.m. to 4:30 p.m. India Standard Time -
  Phone: [phone].