Wireless improves operational efficiency at brewery
16 Jun 2010
Pilsen, Czech Republic – Czech brewer Plzensky Prazdroj, part of SABMiller, has reported significant productivity gains following a recent control system upgrade – from an existing Siemens S5 control system on its kegging line to the Siemens S7 system, incorporating ProfiNet wireless communication.
The company has noted reduced downtime due to enhanced alarming functions that allow its engineers to find faults faster and quickly rectify them. There has also been a quicker resumption of power in the event of a power outage, while a reduction in numbers of PLCs has meant the brewery is no longer reliant on inter-PLC communications – where problems had proved difficult to diagnose and remedy.
The brewery initially engaged Siemens Solution Partner and FMA Process Engineering to advise on the project, with the goal of removing any potential maintenance and downtime issues, and loss of productivity caused by an old legacy system.
The kegging line at the Pilsen plant uses three automated carousels that pre-wash, wash and fill kegs 24 hours a day. The line handles 1,000 kegs an hour so it was imperative that its new control system could keep pace with this level of production. The carousels, which have been in operation for more than 15 years, were each equipped with 12 S5-95U PLCs communicating to a S5 115U over a Sinec-L2 network.
The line had used slips rings to bridge the Sinec-L2 to the carousels. While this worked adequately, limited network throughput meant that it was not suitable for high-speed data transmissions as part of a new control system.
To bring both the performance and reliability of the wireless communication network on-site up to benchmark standards, FMA installed a system using ProfiNet and an Industrial Wireless Local Area Network (IWLAN). This was designed to provide seamless connection of the ProfiNet network, controllers and I/O modules.
In addition, the existing Siemens S5 software was converted and re-engineered to provide the functionality required to accommodate the upgraded system and HMIs throughout the site have been upgraded to OPs to provide enhanced operator control. The goal was to ensure a more efficient control system.
A total of 14 existing S5 115U and S5-95U PLCs were combined into one CPU416-3 PN/DP processor. All associated I/O was rewired to ProfiNet variants of both ET200M and ET200S remote I/O.
On both the pre-washer and washer carousels, the existing 12 S5-95U PLCs’ control was combined into a single ET200S CPU and the remaining stations converted to ProfiNet ET200S remote I/O devices. On the filler carousel, the existing 12 S5-95U PLCs’ control was distributed across two ET200S CPUs and the remaining stations converted to ProfiNet ET200S remote I/O devices.
FMA engaged Daconi, a company specialising in wireless networks and technology, to conduct a wireless survey, using WiFi tools and imported plan drawings of the plant area. The radio coverage of each access point was measured and the best locations for access points and antennas for the wireless clients was established.
The IWLAN system was configured to work in the 5GHz band since the wireless survey showed some sources of wireless interference in the 2.4GHz band.
The 2.4GHz band is the more prone to interference because it is the general-purpose Industrial, Scientific and Medical band (ISM), which is now widely used by many types of equipment.
The system included Siemens Scalance Industrial WLAN access points that transmit ProfiNet wirelessly at the data rate of 54 Mbit/s between SCALANCE W786-1PRO access points and SCALANCE W784-1 gateway clients providing seamless connection of the ProfiNet network, controllers and I/O modules.
Each rotating carousel was fitted with a panel-mounted SCALANCE W784-1 operating in WDS (wireless distribution system) mode using an externally mounted omni-directional dome antenna for 360° radio coverage, as the wireless survey showed that this antenna performed better than a standard Dipole type. The W784-1 units communicate with two girder-mounted IP65-rated SCALANCE W786-1PRO access points utilising internal omni-directional antennas.
