In my previous blog entry, Defining Your Next Network Architecture: Topologies and Global Standards, I addressed two topics to consider when moving from the “bus” to the “net”. Here is the next topic I feel you should consider.
Cost Effectiveness – how can we lower the cost and not lose functionality?
- Find a solution that requires fewer IP Addresses. In an ethernet based network, every IP Address has an associated cost tied to it. With fewer IP Addresses, you need less ethernet switch ports, fewer shielded network cables, and lower other physical cost involved with an ethernet solution. With fewer IP Addresses to monitor, you can observe any changes or network communications problems faster, which leads to more uptime ($).
- Find a solution that allows for easy device replacement. With Profibus and DeviceNet, swapping out a device was as easy as setting a few dip switches and connecting the new device to the network. Look for products that can be replaced similarly, by either the device’s addressing method or by the PLC’s replacement function. I would consider looking at alternate ways to have field devices replaced that require no addressing. Anyway you go faster replacement equates to less downtime ($).
- Find a solution that is easy to integrate. Look for vendors who offer Function Blocks and Add-On Instructions that eliminate much of the confusion on how to integrate a product into the PLC logic. With provided Function Blocks and Add-On Instructions, you can focus on programming the machine’s function, rather than battling configuring and programming the field devices. With easier integration, machines can be built faster, or devices can be added to existing machines quicker, which all adds up to more throughput ($).
- Find a solution with more IP67 options. There is no arguing that an IP67 device is more expensive than an IP20 when put head to head, but an overall IP67 solution is less expensive with everything considered in the installation. First, more IP67 products reduce control cabinet space and remove the need for small junction boxes. By using smaller cabinets or no cabinets is a huge saving, as well as, a smaller cabinet needs a smaller air conditioning unit. Another way to save is to consider IP67 power supplies, which can help greatly, reduce cabinet sizes and need for air conditioning units. IP67 devices also allow for less cabling and wiring time. By using more IP67 devices you can reduce cabinet size, lower cable costs , and reduce labor time, while being Green environmentally, as well as, fiscally ($).
My upcoming blogs will look at Diagnostics, Scalability & Flexibility and Trends in the market, which you should consider in your next network architecture.