The analog annunciator unit is used in a variety of applications requiring monitoring of analog quantities such as temperature, current, voltage, power, etc. in power plants, substations and industry. The equipment is also used in off-shore installations. For temperature measurement standard Pt or Ni sensors are used. For measuring electrical quantities measuring transducers with standard mA or V outputs are employed.
The annunciator units can be used as independent stand-alone units, or they can be integrated via a fibre-optic bus to form complete supervision, event sequence reporting and data acquisition systems.
The channels of the analog annunciator unit measure voltage, current and resistance via sensors or transducers in the process. Further, contact signals can be wired to the input channels. The signal type can be separately set for each channel.
The channel inputs are galvanically separated from earth and from the digital part of the annunciator electronics, but the channels are galvanically interconnected. This arrangement facilitates the supervision and the indication of earth faults in the transducers or the transducer wiring.
The alarm channel inputs accept the following signal levels: 0Ö5 mA, 1Ö5 mA, 0Ö20 mA and 4Ö20 mA, 0Ö1 V, 0Ö5 V, 1Ö5 V, 0Ö10 V and 2Ö10 V. The following standard sensors types can be used for temperature measurement: Pt 100, Pt 250, Pt 1000, Ni 100, Ni 120, Ni 250, Ni 1000.
Further, any Pt or Ni signal within the range 65Ö1000 Ω, potentiometric signal within the range 0Ö200 Ω, 0Ö500 Ω, 0Ö1 kΩ, 0Ö2 kΩ, 0Ö2.5 kΩ, 0Ö10 kΩ can be used and scaled. For the resistance sensors two- or three-wire connection can be used.
In addition, the input channels can be activated by a making or a breaking contact.
The values measured can be shown as numerical values, bar graphs or curves on the dot matrix display on the front panel. The same information can also be read by a superior system via the serial interface.
The content of the event sequence register can be read on the display. The total system can be configured by means of the push-buttons and the display on the front panel, or via the serial interface.
When a measured signal exceeds or falls below the set start value of the channel a visual indication is obtained on the alarm panel. At the same time the acoustic alarm output contact picks up and, if configured, a group alarm relay operates. The event thus generated is stored in the event register.
Any information generated in the annunciator unit can be read by a hierarchically superior system via the serial interface.