Bus bar vs cable based/serial Pick to light – Pros & Cons

Lately light directed picking technology has emerged as the most popular picking methodology & it has become an integral part of order fulfilment especially for ecommerce, retail, FMCG & auto components..etc industries. In case of smaller warehouses, to achieve the required throughputs, and to reduce manual errors; in case of larger warehouses, Pick to light are used for various applications like zone picking, cluster picking, batch picking etc. Whatever be the application, the goal is to amplify the picking with the speed, accuracy, and the ease of working offered by PTLs.

Every pick to light device will be assigned with a location code of the bin/shelf/rack/workstation/position on which this device is mounted and the software of the pick to light device communicates constantly with the warehouse management system or ERP solution or any warehouse control system. Whenever a picking operation needs to be performed, picker scans the barcode of the crate/tote in which the ordered items need to be kept after picking, correspondingly the pick to light device of the location which contains those ordered items gets illuminated along with indicating the no. of items to be picked on the LED display. After picking the items, the picker must acknowledge the pick by pressing the light, this information will be duly communicated in real time with the WMS/WCS/ERP software of the warehouse.

Despite the very light hardware of the product, it is very critical to properly implement it in terms of mounting the device and properly program & integrate in terms of software. Since the early days of pick to light invention, pick to lights have been installed using the serial cable system, where in the devices will be mounted on the racks and get power connection using these serial wired cables. However, the distribution challenges of the serial cables for the electronic power transmission prompted the way for the busbar trunking system. So, the same transformation has been passed on to the implementation of PTLs, so bus-bar enabled PTL mountings are a common sight of the warehouse today.

At Addverb, we offer Rapido, our pick to light solution in both cable based and bus-bar methods; similarly, many players also do offer both these solutions. So, through this blog, let us understand the differences between busbar vs cable based PTL implementations.

  1. Design friendliness – Bus bar based PTLs are compact in design, hence occupy less space, whereas cable based PTL systems require more space because of bending radiuses and the spacing required between parallel cables. Hence busbar based PTL will be beneficial when there are many PTL implementations. In terms of aesthetics and maintaining the entire system, busbar based PTLs look clean and easy to do maintenance activities instead of the clumsy cable based PTL system.
  2. Implementation ease– Cable based pick to light systems are resource intensive both efforts & cost, whereas with modular structure, the busbar trunking PTL installation is quite faster and installation error are practically zero due to the safe and user-guided connection technology.
  3. Flexibility — In the busbar trunking system, PTL units will be mounted on the tap off points of the trunking system, this creates a variable distribution system for linear and / or area-wide, distributed power supply for the entire PTL system. This provides flexibility and unlike the fixed cable-based units, it doesn’t require intensive planning and implementation. The easy retrofit nature of the busbar based PTLs plays a critical role in scaling up or down the entire PTL system.
  4. Voltage fluctuations – Busbars have better resistance than cables, especially to short circuits due to their strong design architecture vis-à-vis to the traditional cable based PTL system. The minimum distance between the conductors inside the busbars induces less resistance and the optimal distribution current density reduces the resistance. This in turn reduces the voltage loss when compared with the traditional cable system.
  5. Reduced Loss of Energy:Busbars have lower resistance than cables. Hence the loss of energy due to transmission and distribution is lower in Busbars. Busbars also have a limited growth of reactive power to operate compared to cable systems.
  6. Highly durable – Since the design is compact and has a metal casing with well-defined surface, busbars can absorb heat generated while transmissions and distribution of electricity in the walls of the enclosure. The system of cooling is much better than traditional cabling system.
  7. Increased safety – Busbars are fitted with a steel casing and the chances of getting damaged by human actions/rodents/any other such accident is lesser as compared to cables, on the other hand cables are more exposed and are susceptible to the environmental changes. Also, busbar trunking system will have standardized products across its implementation, as against the cable system.

The above is a short comparison of busbar vs cable-based pick to light systems. Despite being superior in its functionality and safety aspects, still cable based pick to light system is preferable to some majorly due to the implementation challenges, familiarity with cable based PTLs or the structural systems present inside the warehouse/a facility.