OmniWatch mounts into a panel and features a backlit LCD operator interface with intelligent soft-key controls for programming and interrogation. One of the differentiating features is the use of plug-in PLC-style modules at the rear for CPU, power, communications and I/O. This design makes the product ideal for maintenance and expansion.
It is specially designed to monitor and protect motors, compressors, pumps and fans etc where a number of variables on the machine need to be monitored. The product is a simple solution to the many challenges associated with the monitoring and protection of this moving machinery as it combines five separate functions in one compact and easy-to-use package.
These include:
p Signal conditioning,
p Dual setpoints per input,
p Digital process indication.
p Alarm annunciation.
p Sequential events recording.
OmniWatch also has a built-in Conet network port so that data can be transmitted over a twisted pair link up to 10 km away, typically to a scada, PLC or DCS system. This can be expanded to any distance using plug-in network interface modules (NIMS) which either expand the Conet LAN on-site or enable the OmniWatch to connect to other instrumentation via Modbus. Thus data from water quality analysers and similar equipment can be transmitted back to a central scada using OmniWatch.
Machine monitoring requires a mix of input types, including thermocouples, RTDs and 4-20 mA loops, the latter typically from separate flow, pressure, temperature and vibration transmitters. Thermocouples, RTDs, mA and mV signals are input directly into the OmniWatch which provides full isolation (1500 V r.m.s.) plus inter-channel isolation. Thermocouple and RTD inputs are linearised and provide two adjustable setpoints (alarm and trip) plus a 4-20 mA retransmit output for each input.
The display has been designed with practical user requirements in mind. The operator can view any input value (eg 124,2°C) together with that channel's setpoints and then scroll through all inputs one-by-one. It is common for operators on some plants to record all input values at fixed intervals, writing these down on a clipboard. OmniWatch makes this easy by setting the display to scroll through the various inputs every 5 s, giving the operator plenty of time to write these down. Of course, with the built-in networking ability all of this information is available instantaneously at a scada master station, eliminating the need to manually record readings. As a further enhancement, a DDE server can be used with Windows for engineering staff to browse or collect information for analysis.
The built-in history log of the last 64 events on site is a particularly useful feature for maintenance personnel as they can diagnose machine conditions without having to contact control room operators or rely on scanty information from shift workers. By scrolling up and down through the log, a clear sequence of events is presented to the technician who is then in a far better position to rectify any fault. An event is automatically logged when an input exceeds the setpoints for that channel. The events log is particularly useful in unmanned applications where technicians may arrive hours after a fault has occurred. If, however, OmniWatch is connected to a local area network, then the time-stamped events are automatically transmitted to the host device or master station where they can be displayed, filtered, logged and printed.
A common requirement in industry is for operators to perform functional tests on monitoring equipment on a daily, weekly or monthly basis. OmniWatch has built-in self-test features that make this task very easy, reporting any faults to the operator via the display. It also performs a self-test on power-up. Because alarm annunciation is such an ingrained 'culture' in remote site monitoring, OmniWatch has a built-in annunciator that adds functionality not found on other machine monitoring instruments and eliminates the need for a separate instrument. Acting upon the setpoints, it provides an audible warning device and silence, accept, reset and test pushbuttons. The choice of three alarm sequences together with the two group alarm relay outputs makes OmniWatch ideal for machine alarming and protection applications, especially in those plants where alarm annunciators are commonly used.
Configuration is done via the front panel where the user selects choices presented. The last line of the display is used by the intelligent soft keys whose functions change to suit the particular menu and mode. For instance they are used for both navigation and data entry. The set-up file is stored in battery backed-up memory and may also be uploaded to a PC via the programming port for storage to disk or duplication into another OmniWatch if required. Set-up can also be accomplished using PC based tools and downloaded into the OmniWatch, either from the programming port using RS232 or over the Conet network which may be up to 10 km in distance.
Omniflex personnel have over three decades of experience in designing, manufacturing and servicing instrumentation for the water and wastewater industries.
Omniflex
(031) 207 7466
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