Reliable Data Control
Designed to operate within harsh environments, fast, high-security Lynx switches from Westermo are being used to develop an Ethernet redundancy ring for efficient data control and monitoring at a mining plant in the US
Fairmount Minerals are one of the largest US producers of industrial sand. The company’s Illinois-based subsidiary, Wedron Silica, have been in operation for over 100 years, producing high-purity, round-grain silica sand, which is sourced from St. Peters Sandstone – a 200 million year old sand deposit running from Minnesota to Oklahoma.
More than 50 hourly and 10 supervisory personnel are involved in the production of 10,000 tonnes of sand each day. The plant’s biggest producing segment is for the fracturing sand market.
Hydraulic fracturing sands, known as ‘frac sands’, consist almost entirely of quartz or silica sand, and are used as proppants in oil and gas wells. Frac sand treatment is the forcing of a concoction of frac sands, viscous gel and other chemicals down a well to prop open fractures in the subsurface rocks to create a passageway for fluid from the reservoir to the well.
With the Wedron Silica plant operating 24 hours a day, seven days a week, all production is managed via an Ethernet network, which exchanges data from high-pressure hydraulic mining cannons. In addition, data from cameras linked to the control centre via fibre optics, help to control and adjust truck loading, as well as the sand drying rooms.
Data monitoring and control systems, therefore, need to be of the highest reliability levels, especially in harsh industrial environments, such as mining. ‘Our data network has been working on Ethernet protocol for 10 years but this is the first time that we have installed a full redundancy ring,’ said Frank Barnes, technical manager at Wedron Silica. ‘There were several reasons for choosing Westermo’s Lynx range of switches, such as the strong harsh-environment compliancy, the off-the-shelf redundant ring capability and a fast recovery time of 20ms.
‘In particular, we appreciate the easy configuration and monitoring of the switches as well as the free software updates. We also had a very close technical collaboration with Gross Automation, Westermo’s distributor for North America.’
Lynx switches in operation
The ring portion of the network comprises 11 Lynx 1400-series switches and six Lynx 400-series switches on branch runs. These switches are located in the plant process buildings and are individually named for their location. All are mounted in dust proof boxes and powered by two 24V DC power supplies connected to a battery backup. In the event of a power outage, the ring network remains powered for over two hours.
All control and monitoring information is passed on to Westermo’s network. The Lynx 1400 and 400 both support IMGP protocol (Internet Group Management Protocol), which provides filtering techniques to control the flow of data around the ring in a way that optimizes the bandwidth and secures the network operation.
IGMP is used by IP hosts to register membership in multicast groups to the closest multicast router. The job of the router is to periodically send out a ‘host membership query message’ to remain updated on group membership for the local network. To efficiently utilize bandwidth and reduce traffic, multicasting is used when data needs to be sent to numerous users on the network.
IGMP snooping requires the switch to examine or snoop Layer 3 information in the IGMP packets sent between the hosts and routers. When the switch receives the IGMP host report from a host for a particular multicast group, the switch adds the host’s port number to the multicast table entry. The switch removes the host’s port from the table entry if it receives the IGMP leave group message from a host.
With IGMP servers (routers) included in the Lynx Ethernet switches, no external IGMP servers on the network are required. To provide further technical convenience, the multicast filters are updated within 20ms in case of any network failure.
The Lynx switches fully support QoS (quality of service) with four priority queues and strict priority scheduling, along with HoL (head of line blocking prevention). The 1400 and 400 have military-like designs with full metal housings.
Operating under a wide temperature range, from –40°F to 158°F, both have an extensive DC power range from 19V to 60V but with low power consumption. The switches have no moving parts or electrolytic capacitors, are DIN rail-mounted and support long cable.
Westermo Data Com Ltd, Unit 14, Talisman Business Centre, Duncan Road. Park Gate, Southampton SO31 7GA; tel: (01489) 580585; fax: (01489) 580 586; email: sales@westermo.co.uk