Software that reads Solartron Orbit measuring probes and makes pass/fail judgements, for a manufacturer of gauges and workpiece measuring systems

How the brief came about

The challenge in this case was to bring the values from multiple measuring probes onto one screen, along with pass/fail results and a measurement history for every workpiece. The customer is a manufacturer of gauges and workpiece measuring systems. The customer's measuring set uses multiple contact measuring probes connected together on a Solartron Orbit network, plus IBR measuring instruments whose values also have to be read.

Probes on the Orbit network have no connectivity support from the manufacturer, so the customer wanted software that reads values from every probe, makes pass/fail judgements and keeps measurement results as a history that can be pulled for reports.

Requirements and constraints

The system had to work with the measuring instruments the customer already had and fit the users' inspection procedure. The main requirements are as follows.

• Read values from multiple measuring probes on the Solartron Orbit network through the Orbit protocol (a data communication format), with no connection software available from the manufacturer
• Read values from IBR measuring instruments through the IBR protocol in the same system
• Show the values of all probes at once in real time, along with the pass/fail result for each channel and for the workpiece
• Let users select the workpiece model before measuring, and record every result with the date and time, operator, model and workpiece number
• Allow calibration with a master workpiece from the system's screen, and export measurement results as Excel files

Why did the Orbit protocol reading component have to be written in-house?

We wrote the Orbit protocol reading component ourselves because the probes on the customer's Solartron Orbit network have no connectivity support from the manufacturer. The software therefore has to communicate with the Orbit network directly, and it reads IBR measuring instruments through the IBR protocol in the same program.

Once values could be read from all channels, the remaining work was the users' inspection procedure: selecting the model, measuring, judging the result, recording and calibrating. We built this part as a web application, which users log in to and use through a web browser.

Deliverables

We delivered a web application with reading components for the Orbit protocol and the IBR protocol. One measuring round in the system runs as follows.

1. 1

   Log in and select the workpiece model

   The user logs in, then selects the workpiece model to measure. The system records the model with every measurement result.

2. 2

   Read values from all probes at once

   The measuring screen shows the value read from each probe in its own channel, with pass/fail (OK/NG) status lights for each channel and the overall result for the workpiece.

3. 3

   Record every result

   Every measurement is recorded as a row in the history table, with the date and time, operator, model, workpiece number, status and the value of each channel.

4. 4

   Calibration with a master workpiece

   The calibration settings page allows calibration one channel at a time or all channels at once, referencing values from a master workpiece (a prototype workpiece of exactly known dimensions).

5. 5

   Excel report export

   Recorded measurement results are exported as Excel files for quality reporting or further analysis.

How did this system extend into a second phase?

This system extended into second-phase work in 2020, when the customer engaged us to make the measuring set work with a slide rail controlled by a PLC (programmable machine controller). The second phase included reworking the calibration system to work with the slide rail. Details of that work are in the case on PLC control of the workpiece measuring set's slide rail.

Confirmed results

We delivered the software that reads Solartron Orbit measuring probes and IBR measuring instruments to a manufacturer of gauges and workpiece measuring systems in 2019. The delivered system shows the values of all probes and the pass/fail result on a single screen, and can export measurement history as Excel files.

Acceptance of the system can be confirmed from the follow-on work: in 2020 the same customer engaged us for a second phase, to make the measuring set work with a slide rail controlled by a PLC. This case has no business performance figures, so we report only the delivery and follow-on work that are supported by documents.

What we learned

This work offers the following principles for integrating measuring instruments into a system.

• Start with the measuring instrument's protocol. When an instrument has no connectivity support from the manufacturer, the first task is to read values from every channel completely and reliably, before designing screens or reports.
• Measurement results must always be tied to their measurement context. This system records the date and time, operator, model and workpiece number with every result, and calibrates channel by channel with a master workpiece, so each row of results can be checked retrospectively.
• Measuring instrument integration work needs its scope and test plan defined before development. In this project the scope was still not settled during development, and testing did not go according to plan. During the project we changed our development method to Scrum (development in short, continuous cycles).

Can this approach be used with the measuring instruments in your factory?

Yes. If your measuring instruments output values through a readable communication protocol, you can take the same approach as this case: read every channel into one software application, make pass/fail judgements, record results with the workpiece model and export reports. The part that needs adapting is the reading component, when your instruments are a different model or brand.

• Compile the models and communication protocols of all your measuring instruments, as these determine how much of the connection component must be newly written.
• Document the list of workpiece models, measuring points and pass/fail criteria for each model before development begins.
• Agree the test set and acceptance criteria together from the start, so that testing can follow the plan.