Question Help with using modbus RTU with Sim tools

hi, I’m trying to figure out how to connect my T3DL motor drivers to Sim tools but they don’t support simple serial instead they use modbus RTU which I don’t know how to get SIM tools to communicate with my motor driver.

I was planning on using an Arduino to communicate between the computer and the motor driver, but I am open to switching to something else if that turns out to be a better option.

Edit: I found out that my driver has a (step/dir) control port that I can use to which might be easier than the modbus.

Modbus is typically used for point-to-point movement commands like for a pick&place machine or a robot where the destination position is known in advance and the timing and trajectory doesn't matter exactly. You can send a position command to each axis one after another and get back a "position match" message back when all axes have reached the destination. The servo drive has an internal motion planner that handles acceleration and decelleration ramps.

Real time and simultanous movement is better implemented with step&direction signals or analogue speed command. You'd need a very high data rate to do this with any kind of digital communication interface (at least 1Mbd). There are systems that support it (EtherCAT for example) but they are very complicated and therefore not very common in the DIY area.

However, Modbus can be very useful to transfer configuration and diagnosis data.

Typically at the speeds we want to run at you need to pulse in the 500khz range. The Uno and Leonardo have three PWM timers that could be used for the pulse signals. Controlling the frequency is a bit tedious and there are a limited number of frequencies.

The Teensy has 16 independent frequency generators which use the TI FlexPWM hardware. Downside is that it is 3.3v.

You can also buy a Thanos controller if you just want it to work.