Weidmuller G478 Ultra SlimPak - Manual (Page 3)

A major advantage of the G478 is its wide ranging capabilities and ease of configuration. The G478 enables
virtually 99% zero and span adjustability. Any 2Hz range from 0 to 10,000Hz can be converted to a full scale
output signal (e.g. 0-2Hz/4-20mA or 9998-10,000Hz/ 4-20mA).
Unless otherwise specified, the factory presets the Model G478 as follows:
Input Range: 0 to 1000Hz
Sensitivity: 1V RMS
Output Range: 4 to 20mA
Note: "Sensitivity" refers to the noise rejection level or the trigger threshold of the input.
For other I/O ranges, refer to Table 1 for output range (SW1, 1 through 8) switch settings and to Table 2 for
sensitivity switch setting (SW1, 9 & 10). For quick and easy calibration mode reference, see the step-by-step
flow chart in Figure 1.
1. With DC power off, choose the desired output voltage/current range from Table 1 and set position 1
through 8 of the output switch selector (SW1).
2. Set the Input sensitivity switch (SW1, 9 & 10) to LO for input amplitudes between 150mVp and 50Vrms,
with noise rejection to 1Vp. Set SW2 to HI for input amplitudes between 500mVp and 150Vrms, with noise
rejection up to 10Vp
Do not attempt to change any DIP SWITCH settings for the output (SW1) while power is applied.
Severe damage will result!
1. Connect the input to a calibrated frequency source and apply power. Wait 1 hour for thermal stability
before monitoring the voltage or current output.
2. Adjust the input frequency to the desired maximum and observe that the output has increased and is
sensing the input. If this is not observed, turn the sensitivity potentiometer in a counter-clockwise direction
until the output changes proportionally to the input.
3. With the green LED on press the CAL button once to enter the calibration mode. The yellow and green
LEDs should now be on.
4. Input the maximum desired frequency (if not done already) and press the CAL button to store. The yellow
LED should now be the only LED on.
5. Input the minimum desired frequency and press the CAL button to store. The green and red LEDs should
now be on.
Note: The most reliable way to input 0Hz is to short circuit the input pins (41&42).
6. To precisely adjust the maximum output, adjust the input frequency until the output reads within ±0.1% of
the maximum selected output range. This typically occurs near 90% of the HI input frequency. Press the
CAL button to store the value. The red LED will now be on.
7. To precisely adjust the minimum output, lower the input frequency until the output reads within ±0.1% of
the minimum selected output. This typically occurs near 10% of the HI input frequency. Press the CAL
button to store the value. The yellow and red LEDs should be on. The green LED should be dim.
8. Press the CAL button one final time to exit the calibration mode. The green LED should now be on.
9. Check the minimum and maximum input-to-output calibration. Repeat steps 1 through 8 if calibration is
not within desired specifications.
Note 1: To skip Steps 6 and 7 (output adjustment), press CAL button two times after Step 5.
Note 2: Removing power to the unit at any time before Step 8 will restore previous settings and calibration.
If the amplitudes of the input frequency is within the sensitivity parameters (i.e. 150mVp - 1Vp for LO and
0.5Vp - 10Vp for HI), then the sensitivity parameters can be set for optimum noise rejection.
1. Set the input near midrange (50% input) or to a frequency that exhibits the minimum pulse amplitude.
2. Turn the sensitivity pot (SENS) clockwise (CW) until the output drops to minimum.
3. Turn the sensitivity pot counter-clockwise (CCW) a turn or two until the output returns to the previous
level.
4. Run the input through the full frequency range to make sure that the pulses are sensed at both the low
and high input frequencies. If the output drops out during this test, when the input freq. >0% then turn the
sensitivity pot counter-clockwise another turn or two until the output picks up. Repeat to validate sensitivity
settings.
Configuration
WARNING:
Calibration
Optimal Sensitivity