Measurement Computing Personal Daq/3000 Series - Manual (Page 63)

Using the Hysterisis Function
Update Mode: N/A, the Hysterisis option has a forced update built into the function
Criteria Used: window criteria for above and below the set limits
The figure below shows analog input Channel 3 with a setpoint which defines two 16-bit limits, Limit A
(High) and Limit B (Low). These are being applied in the hysteresis mode and DAC Channel 0 will be
accordingly.
In this example Channel 3’s analog input voltage is being used to update DAC0 as follows:
o
When outside the window, low (below Limit B) DAC0 is updated with 3.0V. This
update will remain in effect until the analog input voltage goes above Limit A.
o
When outside the window, high (above Limit A) DAC0 is updated with 7.0V. This update will
remain in effect until the analog input signal falls below Limit B. At that time we are again
outside the limit “low” and the update process repeats itself.
Hysteresis mode can also be done with P2C digital output port, or a timer output, instead of a DAC.
Limit A
Limit B
Detection
DAC0
Channel 3 in Hysterisis Mode
Ch 3 Analog
Input Voltage
Personal Daq/3000 Series User’s Manual 887894 Setpoint Configuration for Output Control 6-9