Doing more with less is everybody’s mantra these days, and Acromag has chimed in with a new line of rugged, high-density Ethernet I/O blocks for distributed I/O and SCADA applications with analog input. ES2161 and ES2162 do more in less space and use fewer IP addresses to do it, plus they meet that other all-important customer need—speed.
“EtherStax Models ES2161 and ES2162 meet three basic user needs,” says Don Lupo, director of sales and marketing, process products, for Acromag. “First they meet the need for high-density/channel counts of analog measurements over distributed Ethernet networks. Each device supports up to 32 channels of differential analog inputs, and interface the signals to Ethernet devices or controllers with Modbus TCP/IP or UDP/IP protocols. The packaging includes on-board pluggable terminal blocks and is stackable, so users can design high-performance and high-speed systems at densities of almost 200 differential analog channels in a 19-inch wide space inside a rack of panels. Another benefit of higher densities means using fewer IP addresses and faster system throughput speeds.”
ES2161 and ES2162 also mean users can “Ethernet-enable” virtually any analog sensor, adds Lupo. “The combination of ES2161 and 2162 and the ability to cable to industry-standard 7B and 8B isolation amplifiers means they support DC current, CD voltage, DC millivolts, thermocouples, RTDs, potentiometers, strain gages, load cells, frequencies and more.”
Finally, these products also meet the need for isolating analog measurements on a per-channel basis.
In addition to the larger channel densities and counts, ES2161 and 2162 have fast scan rates up to 1 kHz on the inputs. They also natively support Ethernet 10Mbps/100Mbps communication speeds. The overall system throughput speeds can approach sub 10ms speeds over Ethernet, adds Lupo.
The Multiple-Ground Problem
Interfacing to analog sensors presents potential problems of introducing multiple grounds of “ground loops” into the system. ES2161 and 2162 attack the multiple-ground problem in two ways. The inputs are differential rather than single-ended; that is, they don’t share a common input with each other. Differential inputs also help reject common-mode voltages between channels up to 10 Vdc, and they can obtain common-mode voltage rejections up to 1,500 V.
Finally, Etherstax 2161 and 2162 address reliability issues. Every product comes with dual Ethernet communication ports and dual power ports. These ports offer bumpless transfer from one port to the other, and they support standard Ethernet redundancy schemes for spanning tree protocol (STP) and rapid spanning tree protocol (RSTP). They also can be inserted directly into any proprietary redundancy ring from any switch manufacturer. All ports have built-in surge suppression, and ES 2161 and ES2162 are designed for extended operating temperatures from -40 °C to 70 °C.
A hardware watchdog timer can send outputs to a failsafe state, or hold the last value if there is a communication failure. Failsafe SPST 5A fault relays provide local alarming, notification or shutdown if network communication or power fail.
EtherStax are well-suited to many applications for both end users and OEMs. The remote monitoring and control capabilities are perfect for substations, distribution lines and storage tanks. On the plant floor, the rugged construction delivers dependable performance for a variety of distributed I/O functions. In a control panel, the compact design permits mounting in tight spaces. CE and UL approvals are pending. EtherStax are suitable for use in Class I, Division 2, Group A, B, C, and D locations.
For more information, contact Acromag’s Inside Sales Department at (248) 295-0880 or Marketing Communications at (248) 295-0865 or go to www.acromag.com.