How does the OEE Coach data collection mechanism work?
Data Collection Principle
Running or idling
OEE Coach uses a simple and straightforward principle to collect production-data:
When produced product flows from the machine it will be detected by a sensor: each product passing by, the sensor will give a pulse, a signal which will be counted by (the data module of) OEE Coach.
This means: When there are no pulses, there is no product passing by thus the machine in not running. As soon as pulses are being received, the machine is running again and output will be counted.
Remember:
When does a machine run?
For OEE a machine is running when there is output, regardless its speed or quality
When one pulse does not equals one product
In the majority of the cases, counting sensor pulses is a simple 1 to 1 relation: ‘One pulse equals one bottle’.
However there are many deviant situations, that can be configured in OEE Coach. Some examples:
- Products pass by a light-cell in clusters: a cluster of 6 products (e.g. a ‘six-pack’) generate one pulse. So each pulse detected represent 6 products to be counted. In that case we can tell the system to apply a multiplier of 6 for each puls to count individual can’s in a six-pack.
- Product (e.g. foil) is detected by a rotating wheel. Each rotation counts 25cm. We now configure the system with a multiplier of 0,25 in order to measure meters: Every rotation giving one pulse represents 0,25 meter.
Counting GOOD product and SCRAP
When besides good product, also rejected product can be detected, e.g. a checkweigher throws rejected product out, a second (or more) sensor(s) can be added.
We now tell the software for each pulse detected on that sensor, to add a specific type of reject. We recognize these separate sensor since they either have a different IP address or a different port on the data-box.
Advantage of this approach
You do not need to go into the machines ‘intelligence’. The only thing we need to measure OEE is a pulse each time a unit of product leaves the machine. No coding or configuration on the machine needed; a simple sensor usually is enough.
We now can track live and directly whether- and how fast the machine is running.
With this, we can apply OEE Coaches intelligent plausibility checks to detect all kind of mistakes and not plausible data.
Disadvantage
In some (rare) cases it is not possible to get this pulse directly in a simple way from the machine. Sometimes we need to derive it form a PLC, e.g. when complex sensors are being used to create an accurate flow measurement. In such cases, (via) the PLC a pulse can be generated to signal OEE Coach whenever a unit of product leaves the machine.
In such cases however the difficult product detection is being performed by specialized methods which grants OEE Coach to gain correct output data.