The Walchem WMD8 controller is now obsolete and the replacement is the WCT900 controller. The new series has upgraded features; for reference, here is the description of the old model:
WebMaster Dual Cooling Tower Controllers
Up to 12 digital inputs
Up to 8 analog inputs
Up to 4 analog outputs
8 on/off relays
Conductivity, pH and ORP
Ethernet/USB/land modem/cell modem communications
NEMA 4X enclosure and UL/CSA/CE approved
No proprietary software needed to view data or edit PLC programming logic
The WMD series WebMasterONE® is set up to control two cooling towers, with Bleed, Feed and two Biocide control relays for each tower. It has all the capabilities of the other WebMasterONE controllers.
WebMasterONE® controllers are available with Modbus TCP/IP protocol and can communicate with your existing building energy management system, SCADA system or distributed control system over an Ethernet connection. You can view data and alarms using the HMI software that you use for all your other processes. WebMasterONE® operates in Server mode and will respond to requests for sensor readings, alarm messages, relay status, digital input states and more.