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Modbus / Spindle control via Modbus tied to OEM input switches and screen buttons
« on: May 26, 2008, 06:46:01 AM »
This is somewhat strange and maybe I am trying to do something that just isn't possible yet but it almost works.
What I am trying to do (in two parts). I have a VFD for my spindle that I communicate with via Modbus. Without enabling any thing on the Spindle config screen I was able to get it somewhat working. I configured the Modbus and then modified the M3, M4 and M5 VB scripts to set the appropriate bits. I also modified the spindlespeed script to calculate the appropriate value to send out and then send it. I am able to use the MDI screen and execute these scripts and they work fine. I can execute G code programs and they work fine.
What doesn't work is using the Spindle controls on any of the screens. Pressing the Toggle spindle button or F5 doesn't get any action on the GUI. This is probably caused by some code dependency on the Spindle configuration in the Config menu (proven below).
Next I wanted to configure three OEM inputs to run the spindle forward, reverse and stop. These are existing buttons on the control panel on my mill so I figured why not. I mapped them to the OEM codes for CW(110), CCW(173) and I couldn't use Spindle stop because the above are toggles. Not surprisingly it didn't work. It probably doesn't work for the same reason as the GUI buttons also don't work.
Second experiment. I setup Output 4 to map to the Modbus bit that enables the VFD. In the spindle configuration I enable the spindle relays and set both CW and CCW to #4. I enable Modbus Spindle control and set that to #64. I do not enable the spindle motor output because that forces me to assign it output pins for step and direction.
Now the GUI button can at least turn the spindle on/off and control the speed. Also the OEM buttons will cause the spindle to toggle on/off like the GUI. There isn't a true Enable/Disable signal in the OEM codes. In Modbus land Enable is a bit, Reverse is a bit and the speed is a register value. The available codes in Mach don't exactly map to the Modbus control of a VFD.
Another problem with this configuration. The M3, M4, and M5 scripts don't work anymore which means that G code won't be able to control the spindle. When you execute a script it changes the state for a brief instant. It appears that the script changes the internal state of the modbus bit and then something else comes along and wipes it out. I would guess that it is the update from the GUI that overwrites the memory with the state it currently wants to be in.
The questions:
Thanks for any suggestions.
What I am trying to do (in two parts). I have a VFD for my spindle that I communicate with via Modbus. Without enabling any thing on the Spindle config screen I was able to get it somewhat working. I configured the Modbus and then modified the M3, M4 and M5 VB scripts to set the appropriate bits. I also modified the spindlespeed script to calculate the appropriate value to send out and then send it. I am able to use the MDI screen and execute these scripts and they work fine. I can execute G code programs and they work fine.
What doesn't work is using the Spindle controls on any of the screens. Pressing the Toggle spindle button or F5 doesn't get any action on the GUI. This is probably caused by some code dependency on the Spindle configuration in the Config menu (proven below).
Next I wanted to configure three OEM inputs to run the spindle forward, reverse and stop. These are existing buttons on the control panel on my mill so I figured why not. I mapped them to the OEM codes for CW(110), CCW(173) and I couldn't use Spindle stop because the above are toggles. Not surprisingly it didn't work. It probably doesn't work for the same reason as the GUI buttons also don't work.
Second experiment. I setup Output 4 to map to the Modbus bit that enables the VFD. In the spindle configuration I enable the spindle relays and set both CW and CCW to #4. I enable Modbus Spindle control and set that to #64. I do not enable the spindle motor output because that forces me to assign it output pins for step and direction.
Now the GUI button can at least turn the spindle on/off and control the speed. Also the OEM buttons will cause the spindle to toggle on/off like the GUI. There isn't a true Enable/Disable signal in the OEM codes. In Modbus land Enable is a bit, Reverse is a bit and the speed is a register value. The available codes in Mach don't exactly map to the Modbus control of a VFD.
Another problem with this configuration. The M3, M4, and M5 scripts don't work anymore which means that G code won't be able to control the spindle. When you execute a script it changes the state for a brief instant. It appears that the script changes the internal state of the modbus bit and then something else comes along and wipes it out. I would guess that it is the update from the GUI that overwrites the memory with the state it currently wants to be in.
The questions:
- What is the best way to solve this problem?
- If I forget about the OEM buttons, how do I get the GUI and the M3 and M4 scripts to work properly?
- Would a Brain controller have the ability to solve this problem?
Thanks for any suggestions.