Frequently Asked Questions
Everything You Need to Know about IWLAN for Cranes and Heavy Industry
Migrating crane applications to industrial wireless
Installation (durability and flexibility)
Reliability of WLAN communications
 
Migrating crane applications to industrial wireless
Q: The communication cable between the controller end and actuator end is not durable and needs to be replaced frequently. Can wireless technology help?
A: Yes. Industrial wireless technologies can enable cable-free communication for crane applications so the associated costs, such as installation and maintenance, can be significantly reduced.
 
Q: How can we deploy wireless connections on a moving carne?
A: Wireless technology is the best solution for any moving vehicle. Unlike data cable limitations, the connection remains active even if the distance or position varies.
 
Q: We've adopted a specially-made radio transceiver for wireless communication. How is your solution different?
A: Moxa's solution is based on the sophisticated IEEE802.11 standards that deliver many benefits.
 
a. More cost-effiective
b. IEEE 802.11 standards use the license-free bands. You do not need to apply for extra radio
licenses.
c. It provides a higher data rate of up to 54 Mbps for high bandwidth-demanding applications.
d. The technology is more stable and future-proof because it is developed based on open standards, instead of proprietary specifications.
e. It can be easily integrated into Ethernet or other TCP/IP networks.
 
Q: Installing cables in the field is a very critical issue. Is there an easer way to distribute APs and save more cabling costs?
A: Moxa's dual-RF solution provides you with two types of advanced wireless network architectures:
 
a. Wireless bridge network: Dual RFs can create two-way cascade links to form a bridge by running the same device in both master and slave modes. This optimizes the cost-effectiveness and reliability of each wireless unit while maintaining a stable throughput.
b. Mesh Network: Mesh technology provides host-spot-style service; one RF is used to automatically join a self-configuring trunking network and the other one is used to serve local clients simultaneously.
 
Q: We were told that a proprietary radio solution has FH (Frequency-hooping) technology to guard against interference. Does Moxa have an interference-proof solution?
A: Unlike the conventional FH, advanced SS (Spread Spectrum) technologies, including FHSS and DSSS, are also configured in IEEE 802.11 standards to increase the reliability of wireless communications. Moxa's WLAN solution adopts more advanced technologies to effectively prevent interference:
 
a. Redundant wireless connections
b. In addition to standard 2.4-2.5 GHz, 5.15-5.35 GHz, and 5.47-5.825 GHz bands, Moxa provides tailor-made RF band service for special band utilization that can effectively prevent interference problems. Moxa's tailor-made RF band service includes:
 
2.272 GHz to 2.4 GHz frequencies (Europe ETSI)
4.9 GHz to 5.1 GHz frequencies (public safety band)
5.825 GHz to 6 GHz frequencies (special application band)
 
Installation (durability and flexibility)
Q: My application has many moving objects that may block wireless links. What should I do?
A: The combination of Turbo Roaming technology and a distributed wireless infrastructure (consisting of two or more AP units to form redundant paths) provides rapid failover from path-blocking to increase availability.
 
Q: The installation environment for crane applications is usually complex and critical. Since LOS (Line of Sight) and NLOS (No Line of Sight) paths may not always be available, can I still use IEEE802.11 technology for WLAN links?
A: A w ireless bridge network can extend your wireless connections, especially the point-to-point links along LOS and NLOS paths. Unlike WDS, Moxa's wireless bridge network can maintain high communication performance without a reduction in throughput when the number of AP nodes is increased.
 
Q: There are so many troublesome conditions in heavy industry environments. Can the AWK series withstand these environmental obstacles in the field?
A: AWK products can withstand environmental vibration and shocks, and are also IEC61000-4 certified at high levels and even IEC6100-6 certified for critical EMC/EMI in heavy industrial environments. In addition, outdoor AWK models, such as the AWK-6222, provide an IP68-rated housing for resistance to water, dust, and oil in more challenging outdoor environments.
 
Q: Cranes often work in even more critical outdoor environments where wet and salty air will ingress and erode. Can Moxa products operate in these environments?
A: Moxa's IP68 and anti-erosion solutions harden our outdoor AWK's housing to withstand corrosive effects and guarantee continuous operation. The metal case is made of ADC-12, with 96-hour chromating and power coating. In addition to the highest-level water/dust-proof testing, a 168-hour salt spray test is conducted to verify anti-corrosiveness.
 
Q: We deploy our cranes and equipment in a vast area. I am afraid that IEEE 802.11 standard coverage, which supports a 100 to 200 meter transmission range, cannot meet the strict crane operating environment requirements.
A: To overcome the limitations of standard IEE802.11 protocols, Moxa has optimized the algorithm and protocol to extend your application range. Our products are capable of long-distance data transfer over a couple of kilometers.
 
Reliability of WLAN communications
Q: There is so much interference, such as high EMS noise from motors, conductors, and other equipment at plant sites. I am worried that a wireless link will be frequently interrupted.
A: In response to this question, consider the following:
 
a. In fact, not all EMS noise causes interference. Only noise in the 2.4 GHz or 5 GHz band will affect wireless transmissions.
b. The anti-interference technologies, such as FHSS and DSSS, can effectively reduce damage and interruption caused by unexpected radio interference.
c. Advanced solutions, such as special-band utilization and redundant wireless with dual-RF design, provides further protection to avoid the impact of environmental or malicious radio interference.
d. Even when facing unavoidable and large-scale interference, higher-level failover technologies offered by Moxa, such as Turbo Roaming, self-healing mesh, and Rapid Spanning Tree Protocol (RSTP), can enhance system-wide reliability and make your wireless network run non-stop.
 
Q: I want to use my wireless network for video surveillance. However, I am worried that video and audio streams may be affected by other data traffic because they are so sensitive to packet delay or loss.
A: Moxa's AWK series supports WMM (WiFi Multi Media) for IEEE 802.11e and helps optimize your wireless communication with better QoS. You can prioritize the mission critical or delay-sensitive data for more efficient data traffic management and emergency control.
 
Q: I will deploy APs to form a wireless network infrastructure to serve clients installed on the cranes. Can I utilize other services on this existing wireless network? I am worried that unforeseen events, such as broadcast storm or hacking, will affect the existing implementation.
A: It is a good idea to integrate your network application by extending the existing wireless network. To avoid unexpected events or security problems, all services should be properly managed in independent VLANs of a well-planned network. Based on the SSID, two or more clients can be added into a VLAN and grouped into the same LAN segment regardless of geographical locations or specific applications. In addition to VLAN, you can also enable a QoS mechanism to secure the main service and make sure the network runs smoothly.
 
Q: I plan to set up a wireless distributed backbone network by using AP devices to serve client devices and controllers. The backbone is very critical so it must be absolutely reliable.
A: Moxa's mesh technology not only helps form a self-configuring wireless backbone, but also offers redundant self-healing links when the AP link status is changed or broken.
Note: After Q4 of 2010 you can get Moxa's mesh network support with a free firmware upgrade.