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Author Topic: Homann Mod-IO and Digispeed XL on Hitachi SJ-200 VFD  (Read 3605 times)

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Homann Mod-IO and Digispeed XL on Hitachi SJ-200 VFD
« on: May 14, 2007, 11:21:14 PM »
Hi All,

I have a Digispeed-XL connected to a Mod-IO board and a Hitachi SJ200-22 VFD running on Mach3 V2.065. I installed a DPST switch to toggle the Digispeed between Manual and Auto, and have a 5K pot on J4 for manual speed adjustment. In manual mode I'm able to control the VFD just fine. Pretty cool actually.
 
However, when in Auto mode, I am unable to get the Digispeed to work as desired. Turning on the Spindle causes the Zero Speed relay to change and the Control Voltage indicator LED to change (bright red--never varies execpt to turn off) while the Mode LED changes from Solid Red to Fast Blink Red. I'm unable to cause the Lazy double red blink (the condition for Digispeed Enabled but PWM set to zero RPM) unless I disconnect the PWM signal from the cable connecting Mod-IO to Digispeed. Zero RPM on spindle still causes a fast blink. On the possibility that the PWM signal was flipped (Hi for zero and vice-versa), I have set the RPM to 8000, but that did not change anything either. I've also played with the jumper on JP13 but saw no difference (power off on each change so Mod-IO and Disgispeed reset). The jumper remains off the board at thsi time (as I'm unable to determine which position causes what).
 
Here are my settings on Mod-IO:
Dout2 -- not connected to Digispeed as direction not needed for now.
Dout3 -- Configured to Output #1 As Port = 0, Pin = 3, Active Low
Dout4 -- Ports & Pins, Motor/Spindle set in Motor Outputs, Port = 0 , step (PWM) Pin = 4, Active Low
 
In Mach3 the following settings are in place:
In Ports & Pins, Spindle Setup tab/Relay Disable Spindle Relays box is unchecked, and Output is # 1 in both CW & CCW.
Motor Control Use Spindle Motor Output and PWM are both Checked, PWMBase Freq = 50, Min = 0%.
I have tried Modbus Spindle - Use Step/Dir as well both Checked and Unchecked. Currently Unchecked (unclear on the correct setting as I have seen both used in documentation)
 
I have another issue that may be related: The VFD has a nominal 10V 10mA reference voltage "H" (actually 10.57V) that I have running into P1 on J5 on the Disgispeed, P3 is connected to "L" on VFD and P2 is the control voltage "O" going to the VFD. I played with this a bit to find this connection configuration (my initial setting had it working opposite of desired). What is happening is that the Reference "H" 10 Volts is being pulled down to 1 volt (exactly) when in Auto mode, but in manual mode it works fine (Voltage stays at nominal 10V). Intuitively it would seem that the 10mA is insufficient, but that is just a guess on my part.
 
My questions are:
Why won't my PWM signal allow a zero-speed?
Why is my VFD Ref voltage is being pulled down???
 
Sorry for the lack a brevity? I was thinking that more info may help.
 
Any thoughts are welcome. Thanks for your time and attention!!
 
David
« Last Edit: May 14, 2007, 11:22:49 PM by Haysys »