Pulsafeeder Pulsar ECA NEMA4X - Manual (Page 24)

signal. Note that the minimum span, or difference between low and high values, is
2.0 mA. The ECA will not actuate to change stroke length during this process.
T HIS PROCEDURE REQUIRES REMOVAL OF THE ENCLOSURE COVER . T HIS PROCEDURE SHOULD BE
PERFORMED ONLY IF THE AREA IS KNOWN TO BE SAFE FOR ELECTRONIC WORK .
• With the cover removed and power supplied to the ECA, press and release the
white Input Cal pushbutton. The Cal Input LED will blink slowly, indicating the ECA
is ready to accept the low (0% stroke) analog input value.
• Send the low analog signal to the ECA (generally 4 mA) from the signal-generating
device (e.g., PLC). It is highly recommended that you use the actual signal the ECA
will be receiving during calibration.
• When the low analog input value has stabilized (allow 10-15 seconds), press the
white Input Cal pushbutton to accept it as the 0% flow analog signal value. The Cal
Input LED will now blink rapidly.
• Send the desired analog high signal (generally 20 mA).
• When the high analog input value has stabilized (allow 10-15 seconds), press the
white Input Cal pushbutton to accept it as the high (100% stroke) analog signal
value. The Cal Input LED will extinguish, unless the minimum span of 2.0 mA is
violated, then the ECA will return to step 1 above.
Reverse-acting calibration is accomplished by input of a high signal (i.e., 20 mA) as the low
(0% stroke) analog input value, and a low signal (i.e. 4 mA) as the high (100% stroke)
analog signal.
• Replace the cover (see Section Cover Re-installation) and continue with the
output calibration if that function is being utilized.
8.1.2 Analog Input Signal Loss
A failure of the analog input signal is detected if the input signal falls below the
calibrated 0% stroke signal by 0.3 mA. For example, if the ECA is calibrated with a
range of 4-20 mA and the signal falls to 3.6 mA then a Signal Loss failure will be
logged. If the calibrated 0% stroke signal is 0.3 mA or less, no Signal Loss failure
will be generated. Input signals above the calibrated 100% stroke signal are simply
ignored, the stroke position will be driven to 100% and no error condition occurs.
In the event of a loss of analog signal
or an abnormally low signal, the ECA
will drive to the zero stroke position.
The ECA will recover once a valid
analog signal is present and resume
control to the appropriate set point.
8.1.3 Analog Output Signal
Calibration
18