Main Functions
All the function software is fixed in the memory chips. When users install the optional expansion boards or operators make selections via the keyboard, the controller will automatically activate the corresponding functions.
(1) Measurement Functions
a. Instantaneous Flow Calculation
The unit weight signal output by the weighing sensor is multiplied by the unit belt speed signal output by the speed sensor, and the result is the instantaneous flow.
b. Weight Accumulation
The accumulated amount is calculated by multiplying the weight per unit length by the running length and then converting it into engineering units.
c. Automatic Zero Adjustment and Automatic Interval Adjustment
Defining the number of belt loops and the length of the belt is the basis for automatic zero adjustment and automatic interval adjustment. To accurately calculate the belt length, the controller calculates the number of pulses sent by the speed sensor. When the accumulated number of pulses reaches the required number, the controller ends the calibration test, compares the theoretical value with the actual value, and calculates the calibration constant.
d. Automatic Zero Tracking
When the belt is running and the flow is lower than the preset value, the controller performs automatic zero adjustment according to the following steps:
Wait for half of the test cycle time (the display will show "Z").
Complete one zero adjustment test.
Complete the automatic zero adjustment for one test cycle.
As long as the flow value is lower than the preset value of the automatic zero tracking, the instrument will continuously repeat the above steps.
e. One-way Input, Two-way Current Output Signals
Optional input/output expansion boards can be used to obtain one-way voltage/current input and two-way current output signals.
(2) Monitoring Functions
Status prompts
Process alarms
Setting errors
Equipment failures
High flow, low flow, high load, low load alarms
(3) Automatic Control of Feeding Function
The weighing controller provides an independent control current loop, which is usually used to control the feeding amount. The control method is as follows:
PID = Proportion + Integration + Differentiation
The controllable process variable is the feeding amount. The flow setting can be input through the keyboard or set by an external analog signal. The control output is a 4 - 20mA current loop.
