The Walchem WCT900 controller is now obsolete and is replaced by the Intuition-9 Cooling Tower controller. The new series is enhanced, but has similar specs. For reference, here are the specifications of the old model:
Series: WCT900
Electrical: 100-240 VAC, 50/60 Hz
Relays/Wiring: Hardwired or Prewired, with Different Combinations of 8 Relays (powered, dry, or opto)
Digital Inputs: 12 Digital Inputs (state type, flowmeter, etc.)
Sensor Inputs: Up to 8 Sensor Inputs, depending on model
Analog Inputs: Up to 24 Analog Inputs, depending on model
Analog Outputs: Up to 16 Analog Outputs, depending on model