Hi Guys,
Many points have been raised and I think many of these issues are addressed through the use of skyko's p100. I will summarize my understanding below. Please let me know where I am going wrong.
1. Fanuc pulse coders are usually 2,000 or 2,500. From my reading it seems that 2,000 is usually for Fanuc brush motors and 2,500 are the brushless motors that have Hall signals. I am 95% certain my pulse coder is 2,000. According to skyko the p100 is for 2000 count encoder Fanuc motors.
2. Motor speed will usually be slow using a 2000 count encoder and mach 3. However, the ball-screw ratio may improve the speed and the 35 or 45 kernel speed may need to be used. If slow you can use a multiplier to speed things up again. I do not have the information on the ball-screw ratio at this time. However, the skyko p100 comes with a step multiplier just for this purpose.
3. The Model 0 servo uses a F to V converter to provide the tach signal for the velocity unit. This is a frequency to volt converter? I think the p100 can be wired directly to the encoder and it will handle any necessary conversions. For reference I have copied the wiring diagram below. I think it is ok to post here as this is free to download from Skyko.com. Am I missing something? Skyko says it needs the 5v A and B signals from the encoder and nothing else.
Additionally, Skyko says the following: "The Pixie implements a Proportional, Integral, Derivative (PID) control loop using position feedback from the motor shaft in the form of quadrature encoder signals (denoted by channel A and channel B). Each time through the loop, the Pixie calculates analog reference voltages to control the speed and direction of the motor to bring the current actual position of the motor shaft to the desired position (usually commanded by a control host through the step and direction signal lines). It does this calculation 10,000 times per second to achieve and maintain the desired position through a changing load."
4. Regarding the need for +-10 volt to step / dir input cards to interface with Mach 3. Skyko says, "[the p100] has a jumper selectable analog output range of ±10v or ±5v which is compatible with many commercial motor amplifiers." Is this the function needed?
I really appreciate your input.
David