Wireless DNC, MDC and other shop floor devices have some great benefits. When you are considering the question of wired vs wireless, there are some potential issues that you will want to consider. The intention of this article is to help you make an informed decision on whether or not wireless has a role to play in your DNC, MDC or other similar solution.
Wireless shop floor solutions offer many benefits including:
- Ease of deployment
- Ease to move/relocate assets
- Relatively low initial implementation costs
- Can be used where wired networks are not possible
We should of course, consider the potential down-sides.
Potential Down-sides to Wireless on the Manufacturing Plant or Shop Floor
Every conversation about technology should not emphasize only the benefits. It should include an honest, informed discussion about the potential problems. The potential problems with wireless shop floor solutions are:
- They can be vulnerable to outside influences, jamming, and interference
- The hardware is more expensive to upgrade than wired
- Speed and performance (if shared with other devices)
Wireless vulnerability to outside influences, jamming, and interference
The greatest concern for some facilities will be the security of the system – e.g. prevention of unauthorized access to the network. For a moment lets assume that the wireless encryption you are using is up to date, maintained, tested, and proven in terms of security such as the current current Moxa Wireless equipment we recommend as a CIMCO dealer.
Even a secured Wireless Network is Still Vulnerable to Outside Influences
While it is unlikely, it is possible that someone with a inexpensive device and a desire to harm your business can disrupt your wireless network by creating a strong signal that mimics yours causing a direct conflict. The result of this conflict is a disruption of your wireless data and an inability to reliably reach your CNC machines with your DNC or return signals from your MDC system. The only protection from this is Radio Frequency Shielding, which varies based on the materials used and can be quite expensive.
There are simple manufactured devices that jam just about any wireless signal. Here is a video that demonstrates a simple home made wifi jammer which could be used to disrupt your wireless shop floor solution. It is unlikely that you will be victimized by one of these devices, and the devices are illegal to operate (in the US and much of the world), it is a possible situation that a business in a highly competitive industry could face.
What about inside interference?
If you do happen to have a well shielded facility, it is still possible that wireless radios or devices that can interfere within your own walls can potentially disrupt your wireless shop floor solutions. Every cell phone, laptop, many printers and a plethora of other devices contain wireless radios. Every wireless radio can be configured or have a defect that can cause a disruption of your wireless infrastructure.
The key is to be prepared to address these issues, should you be faced with them.
Wireless Upgrade Costs
Wireless hardware has a shorter obsolescence cycle than Ethernet wired devices. Wireless devices cannot be run forever, eventually they will become obsolete and vulnerable to hackers. Keep in mind the cost to replace the devices when this occurs.
The reason for the quicker obsolescence is due to wireless devices using different methods for encryption and communication. Features such as frequency ranges and encryption methods are at least partially locked in to the devices when they are manufactured. As the technology evolves these systems can become obsolete. They become obsolete because manufacturers tend to emphasize the latest wireless specifications, so the older products don’t get the needed security upgrades or just simply can’t support the latest wireless spectrum.
Wireless requires more careful consideration, testing and validation before going through these upgrades. CIMCO does validation testing on Moxa hardware as new versions become available. Because wireless is dependent on both the access point and the endpoint device, this testing is more involved. Considering that wireless hardware itself has a premium of 30-50% over the wired counterparts and the cost can add up quickly.
Wireless Network Speed Limits
Wireless limitations extend beyond just vulnerabilities and long term viability, they are also limited speed. Bandwidth affects how far you can scale and will face bandwidth limitations much more quickly than a wired solution will. DNC and MDC do not use much bandwidth but wifi networks are often shared with other devices. Bottlenecks in your network can affect your DNC, MDC or other wireless connected devices. Wireless networks require more careful planning to make sure adequate signal strength is present to provide a reliable connection.
Wired Ethernet specs when following proper guidelines will provide very high performance at great distances. Simple 100 Mbps gear is more than sufficient for a typical DNC solution. This means Cat5e or Cat6 wired solutions should exceed your needs for the distant future. Depending on your environment this expense may be more or less expensive, particularly when you take into account the potential obsolescence of wireless devices.
One Size Does Not Fit All
Keep in mind, there is no magic bullet, each situation is unique. The best approach is to gather the facts, understand the requirements and determine the best solution. One size does not fit all, especially with wireless DNC and similar technologies.
Planning For Wireless
Now that we know what some of the potential problem areas are and we’ve taken those in to account. What can we do to reduce the risks associated with wireless DNC or MDC? Make sure that the group responsible for your wireless infrastructure has adequate resources to maintain. These are some of the steps that they will likely take:
- Evaluate existing interference utilizing a Spectrum Analyzer
- If outside interference is a concern implement RF Shielding (Construction materials, paint and window film)
- If the data on your network is of sensitive nature perform penetration testing.
- Assist with the creation of policies to prevent inside interference (mobile hotspots to be turned off on smart phones, etc)
Depending on your situation, these costs can add up giving more weight to the Ethernet wired option (to Moxa Nport devices such as 5110A).
Making an informed decision on Wireless Shop Floor Solutions or DNC
Wireless technology is very useful for many things, but you should understand the risks for mission critical wireless DNC or related systems. Truly understanding the risks will help you decide if it is right for you. We carefully review each customer case and don’t push wireless because it is the easy route for CIMCO DNC Max or CIMCO MDC implementations. The best option can only be determined with careful consideration.
Just because we can doesn’t mean we should, informed decisions about wireless shop floor solutions are essential.