WattMaster WHP | Section 4 |
|
|
3.0Loop Controller Overview
3.1How It Works
3.1.1Initialization
On system powerup LED2 remains extinguished for five seconds. After this delay, the LED2 will blink out the address of the controller (Address Switch Setting). The LED2 will then extinguish for another five seconds and then the LED2 will begin blinking a diagnostic code every ten seconds. This code is described in the troubleshooting section. The duration of a powerup initialization sequence is roughly thirty seconds.
During this initialization period, the controller retrieves all operating setpoints from its
3.1.2Operating Summary
There is a standard set of operating instructions that are continuously performed over and over during normal Loop Controller operations. They are listed below.
aRead analog inputs for temperatures, pressures and binary contact closures
bChecks for new setpoints from System Manager or Prism Software and keeps the status values updated for these interfaces.
cLooks for “request to run” broadcast from any installed WHP Controller or from an
d.Set all outputs to match calculations for heat rejection or addition.
e.Store data in internal trend log if ready for another log
f.Broadcasts the operating commands to all WHP Controllers.
g.Tests for lead/lag pump changeover if both pumps are off.
h.Repeat steps
