The following specification covers a comprehensive, programmable, fully automatic Level Control and Monitoring Instrument for continuous level operation.
The Controller shall be panel mounted or wall mounted in a Nema 4X, waterproof, non-metallic enclosure with a clear Lexan viewing window.
The Controller shall be microprocessor based with 24 bit signed integer variables and fully user configurable through five front of panel user keys. The Controller shall display all level and alarm information on its graphical, backlit, LCD display with a resolution of 128 x 32 pixels in bitmap form. Process variables and set point information shall be displayed in digital, alpha, bargraph and trend formats.
All programmable parameters shall be password protected to prevent unauthorized changes. The password shall be user programmable. An ‘on-board’ alarm horn shall be user selectable to activate upon alarm conditions and shall be silenced with any key.The following operational parameters shall be user programmable.
The Myriad LC2 shall monitor the input signal and display the preprogrammed values in engineering units and vertical bargraph format. Four form ‘C’, 5 amp relay outputs for control or alarm shall be provided and be fully user programmable.
Two retransmit analog outputs for remote monitoring shall be standard. One shall be scaleable with respect to the input. An integral audible alarm shall be provided which is user programmable to actuate when a digital set point is reached.
The Controller shall be powered from 230/110 VAC or 24 VDC and will provide 100mA of DC excitation output for the level sensor and other external loads.
All inputs and outputs shall be optically isolated with common negative. Analog inputs and outputs shall be user selectable for 4/20mA, 0-5 VDC, 1-5 VDC and 0-10 VDC. Output relays shall be single pole double throw (SPDT) rated at 5 amps.
A comprehensive diagnostic screen shall be standard, which allows the operator to view the status of all analog and digital outputs in real time.
For SCADA and communication purposes the Controller shall contain two RS485 data ports. Controllers shall be able to be connected in a Network and communicate with each other in true peer-to-peer form, with up to 4,000 feet between nodes.
If used in the panel mount format the controller chassis should be removable without tools or removal of any wiring. Withdrawal shall be through the front of the Din case.
It is the intent of this specification that a standard device be supplied that requires no special software, programming or specialized knowledge.
The Level Controller shall be a Sigma Myriad LC2.