The Digital Hydromaster is a controller which senses level, pressure and maintains a air balance of a hydropneumatic tank and controls for one or more pumps. The Digital Hydromaster consists of a Operator Interface Panel, a Programmable Logic Controller with digital and analog I/O, and a Pressure Transducer. The Hydromaster Operator Interface Panel has 4 function keys, 4 program arrows keys, and a enter key. The Operator selects pre-programmed screens and inputs pressure start and add-air setpoints, time delays, alternation features, and alarm conditions. The Interface Panel has a Graphic Monochrome LCD display with a integral LED backlight. The display size is 3.2", with a pixel size of 128 by 64. One of the menu screens is the HYDRO TANK STATUS. The status screen displays pressure, plus a bar graph, pump and compressor status. Other menu screens allow the operator to select pressure setpoints or time delays.

The Programmable Logic Controller has 2 analog inputs and 2 analog outputs, 14 digital inputs and 10 outputs. The PLC can expand to 136 I/O if required. The analog 4-20ma input is from a Pressure Transducer with a range of 0-100 PSIG. Solid State Probe Modules detect pump stop and air limit levels from the R-B Probe Assembly. Pump and compressor hand-off-auto control switches are provided. Pump and compressor relays are provided and are rated 10 amp @ 120/230v. The R-B Probe assembly is provided for front mounting to the hydropneumatic tank. The Digital Hydromaster standard models are DT2A for 2 pump control.