Setting the C4 Value
Scaling the Analog Speed Signal
Why set the C4?
Every Stagehand motion controller sends an analog speed signal to the VFD telling it how fast to go. Depending on the Stagehand type, this same signal also describes the direction the motor should spin. These speed signals are called Unipolar (speed only) and Bipolar (speed and direction).
The Stagehand Pro 3 &4 and Stagehand Apprentice utilize a 0-5vdc speed signal with seperate direction switches.
The Stagehand Classic and Stagehand Pro 2 utilize a +/-10vdc speed and direction signal.
In either case, the Mitsubishi VFD needs to be calibrated to the analog speed signal coming in so that 100% speed signal results in 60hz output to the motor. Some models have been calibrated at CCI HQ and have a label on the back or on the VFD Keypad showing the value that should be entered in Parameter C4.
Set C4 from A Known Value
CCI puts a small "C4: XX.X" sticker in the top, left corner of the rear of the Stagehand enclosure OR along the top or side of the VFD Keypad
The screen will display a value of X.X (close to 0.0)
Cycle power to the VFD
Set New C4 Value
The Stagehand does not need to be connected to a motor to run the calibration sequence.
For any Stagehand Pro controller:
Set Pr. 800 (control method) to 20
Unplug your motor cable
Set your C4 Value (below instructions)
Set Pr. 800 to 0
The screen will display a value of X.X (close to 0.0)
Jog the Stagehand forward to 100%
Wait a moment for the VFD to beep and flash between your new value and P C4
Release the FWD Jog button
Cycle power on the VFD
Make a label with this number and place it on the back of the cabinet. This number is unique to this drive and gets reentered in C4 if the drive ever gets reset.
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