The OLM200 PROFIBUS exploits camera-based imaging of bar codes: the sensor determines positions and speeds on both straight sections and in curves by scanning a robust bar code label, e.g. on overhead conveyors in monorail systems, as well as on rail-borne shuttles or on storage and retrieval devices that negotiate curves. The sensor achieves a reproducibility of 0.15 mm even at maximum process speeds. This feature, together with resolution that is incrementally adjustable between 0.1 mm and 100 mm, and the high output rate of 2.5 ms, ensures maximum precision in determining the position of mobile, fixed route units. Measurement values are transmitted via the PROFIBUS DPV0 interface. In addition to the Profibus interface, the OLM200 also offers PNP and NPN switching outputs.
Maximal: robust design for optimum availability
Mechanically, thermally and optically, the OLM200 PROFIBUS masters the wide range of conditions found, for example, when overhead conveyor technology is used. The metal housing and the lack of internal moving parts (ensuring that there is no friction) guarantee a high mechanical resistance to impacts and vibrations. The operating temperature ranges from -30°C to +60°C – a value that also applies for the bar code tape. This results in maximum flexibility and reliability in numerous applications. The OLM200 PROFIBUS achieves maximum resistance to ambient light (up to 30 klux) or other optical effects from the surroundings thanks to its self-adjusting LED illumination, which is also designed with redundancy. While these features ensure an already high level of sensor availability, it is further improved by the integrated advance warning of failure: the OLM200 PROFIBUS autonomously signals any need for maintenance (allowing planning by service engineers), preventing unplanned plant downtimes and the resultant costs.
Minimal: integration costs
A variety of features ensure that the OLM200 PROFIBUS can be rapidly and economically integrated. Mounting of the sensor – using the three drilled holes on either side of the housing or the slot at the back – is suitable for almost all situations. In addition, the housing design takes into account the necessary alignment angle. As a result, unlike comparable systems offered for overhead conveyor technology, the OLM200 PROFIBUS only requires vertical alignment to the bar code – taking correspondingly less time. The reading distance between the sensor and the bar code tape is specified as 100 mm or 130 mm +/- 20 mm – such distance tolerances along the drive path shorten commissioning times and ensure reliable position detection. In connection terms, the OLM200 PROFIBUS is compatible with SpeedCon™ and standard M12 plugs – further supporting rapid and simple installation.
Attachment of the bar code tape is also easy: it is affixed along the drive path. Small expansion joints can simply be taped over; an individual bar code can be separated off at a margin to cover larger expansion joints or problem areas. If, during operation, a bar code is damaged or becomes very dirty it can easily be repaired by downloading the bar code from the Internet, printing it on a self-adhesive white label, and inserting it into the corresponding location in the bar code tape.
The OML200 PROFIBUS is the ideal solution for measuring the position and speed of electric overhead conveyor vehicles, rail-borne shuttles, and storage and retrieval devices that negotiate curves. Offering flexible use on straight sections and in curves, the sensor convinces through its low mounting, commissioning and operating costs, as well as high plant availability.