First off, i am new to ladder logic. I do have some experience programming microcontrollers in C. I will try and give a short version and if more details are required i will certainly provide them. I'm just not sure what i want to do is possible (with an AB Micro820 PLC)
What i this pertains to: A horizontal CNC drill spindle.
What i need to do: Install a VFD for the spindle, and be able to use 4 different gear ranges in the transmission. The reference sent to the VFD will need to take gear ratio of current gear into account. The current setup has 7 solenoids, 36 gear ratios, and a 1800rpm motor (no vfd).
What i plan to do: Install an AB Micro820 (and use the free version of CCW), feed the 0-10V reference from the CNC Controller to said PLC. The PLC will need to be able to decide based on the reference voltage what gear needs to be selected. The PLC will facilitate shifting the transmission via outputs to solenoids and a sequence that "bumps" the spindle a few times while proper solenoids are active to shift the gears. Once shifting is complete the PLC will need to output a 0-10V (or pulse train) speed reference that is relative to the gear selected so the VFD will run at the correct frequency for that gear to achieve the requested RPM from the CNC controller.
I by all means am ready to do my own homework as far as getting it done, but before trying to sort this out I'm hoping someone may be able to tell me if such an operation is possible with the given software/hardware, and if not, what do i need to get (i don't mind paying for the hardware but prefer not to spend hundreds - thousands on the software).
I am also up for ideas for a better approach. Any help on this is greatly appreciated.
What i this pertains to: A horizontal CNC drill spindle.
What i need to do: Install a VFD for the spindle, and be able to use 4 different gear ranges in the transmission. The reference sent to the VFD will need to take gear ratio of current gear into account. The current setup has 7 solenoids, 36 gear ratios, and a 1800rpm motor (no vfd).
What i plan to do: Install an AB Micro820 (and use the free version of CCW), feed the 0-10V reference from the CNC Controller to said PLC. The PLC will need to be able to decide based on the reference voltage what gear needs to be selected. The PLC will facilitate shifting the transmission via outputs to solenoids and a sequence that "bumps" the spindle a few times while proper solenoids are active to shift the gears. Once shifting is complete the PLC will need to output a 0-10V (or pulse train) speed reference that is relative to the gear selected so the VFD will run at the correct frequency for that gear to achieve the requested RPM from the CNC controller.
I by all means am ready to do my own homework as far as getting it done, but before trying to sort this out I'm hoping someone may be able to tell me if such an operation is possible with the given software/hardware, and if not, what do i need to get (i don't mind paying for the hardware but prefer not to spend hundreds - thousands on the software).
I am also up for ideas for a better approach. Any help on this is greatly appreciated.
Last edited: