Sterlco GH-F Series Gravimetric Additive Feeder - Manual (Page 44)

Chapter 5: Maintenance 44 of 60
Input Signals to Programmable Controller
The rate monitor system has two main input signals that it uses from the extrusion process:
the weigh hopper load cell, and the extruder speed reference. This, of course, does not include
the operator touch-screen input.
The extruder speed reference is generated from the supplied inductive proximity switch, or is
wrote to the PLC through the optional Ethernet module.
Load cells require +12 volts DC to operate. This is known as the load cell’s excitation
voltage.
Output Signals from Programmable Controller
The rate monitoring system uses several output control signals to control the process. All of
these are very similar in nature.
The surge hopper refill solenoid is controlled by a PLC output.