Interested in implementing a wireless communications network on your production line, on the plant floor, or even expanding the network outside the manufacturing walls? Manufacturers have three key wireless elements to consider, and what may be a surprising solution: WiFi, that ubiquitous IEEE 802.11 standard popping up in cafes and airport terminals across the U.S. Trends include:

1) Control oriented wireless communication is at the core of the production environment. Control over wireless links addresses the need to talk to I/O untethered. A multitude of applications demand the mobility and flexibility of wireless control, including automated guided vehicles (AGVs), gantrys, turrets and others.

2) Manufacturers are taking advantage of the growing ability to monitor and evaluate each machine or operation wirelessly, inside or outside the plant.

3) The merger of manufacturing and IT environments means that office technologies can be used and improved on with manufacturing environment advancements. One of these is VoIP (voice over Internet protocol) over two-way radio.

A WiFi installation exists as a subnet attached to the enterprise-level network. It has a star-network topology with a wireless access point (WAP) at its center and an unspecified number of nodes each linked to the WAP via two-way digital radio.

When a data terminal equipment (DTE) device, such as a handheld computer, enters the WAP’s coverage area, it attempts to connect to the wireless network. Networks can be secure (only DTEs carrying proper authentication codes can join) or open (any DTE can join). Depending on conditions, links can be reliable to roughly 30 m of the WAP indoors and somewhat farther outdoors.

Specific features can ensure I/O application performance. Point coordinated function (PCF), for instance, can create deterministic-like performance over wireless by polling, which is when the access point scans clients in a defined time.

Antenna technologies, including R-coax cable (see below), can communicate with devices that move along a track. The Volkswagen plant in Emden, Germany, uses R-coax cable in critical radio system environments found in mobile screwing stations. Client DTEs communicate reliably with the plant’s control system and assembly line server there.

Wireless can bring together office and industrial domains into a comprehensive wireless architecture, providing plant wide connectivity for solving the needs of both IT and automation

  Bear Island Division of the White Birch Paper Co. sought ways to improve manufacturing processes and find cost savings and efficiencies. At the mill’s remote scale house, truckloads of wood chips, whole-tree-length wood, and chemicals are weighed as they enter and exit the plant.

For years, unplanned telephone line interruptions had plagued the scale house’s telephone connection to the company’s network server. Industrial-grade wireless LAN technology helped eliminate unplanned downtime at the station and reduced labor costs.

An in-bound scale automatically weighs entering trucks and their contents while drivers scan a ticket into the automation system. Information is wirelessly communicated from a directional antenna mounted on the exterior of the facility to an access point at the mill’s servers 1,000 yards away. Replacing phone lines with the rugged wireless LAN system delivered $150,000 in annual savings.

Application note: Wireless at Mt. Olive Pickle

Mt. Olive, NC—Mt. Olive Pickle Co. Inc., the largest privately held pickle company in the U.S., is using voice over Internet protocol (VoIP) technology. Mt. Olive also makes heavy use of electronic data interchange (EDI) technology, using it to receive more than 90% of orders from retail customers and to send invoices to about 80% of customers. So when the new advanced ship notice (ASN) EDI format was emerging, Mt. Olive knew it had to upgrade its warehouse management system accordingly.
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