[TRNSYS-users] problem about the differential controller (Type2)

["Yin Hang" <yhang@purdue.edu>]

Hello,
I have a problem when I use differential controller type2.
For example, I want to control my solar collector loop pump
by using one of this controller.
My control logic is when the outlet temperature of my solar
collector is higher than the inlet temperature of my solar
collector 4C, the pump will be on;
And when it is lower than the inlet temperature for 2C, the
pump will be off.
However, I found the output control signal is fluctuated,
such as it suddenly becomes off even the outlet temperature
is 2C higher than the outlet temperature; and next timestep,
it suddenly on.
Could you help me to fix this problem? I figure it is really
bad since it is un-normal for my pump during true situation.
Thanks.