Oscilloscope as TTL or RS232 source

Hi I’m new to this forum. I am a self learner of Robotics/general electronics and my question may sound clueless but I’ll give a try anyways :slight_smile:

Can I use an oscilloscope or any pulse generator as a pulse source to control motor controllers like SMC04 as long as the oscilloscope or the pulse generator generate compatible and meaningful binary RS232 pulse sequences?

Should the RS232 communication be bi-directional? In other words, does the oscilloscope also need to receive and acknowledge pulse coming from the SMC04? Or would it work just fine in one-way?

Is it possible to daisy-chain multiple RS232-controlled boards under an oscilloscope or a pulse generator as long as each board is set to different address? (SMC04 doesn’t seem to have address setting dip switch but this is a general question, not a specific question to SMC04. Well, all my questions above are general questions not specific to SMC04 for that matter)

Thank you in advance.

Clueless questions are the best kind! If I had a clue, I probably wouldn’t be asking after all. So:

  1. I suppose that if you had a nice enough pulse generator that let you define an arbitrary pulse train (or, of course, one made to generate RS-232 packets) you could set it up to output pulses that would be meaningful to your motor controller. My question is why would you want to, it would be way more work than just using a PC. To test out an SMC04 you could more easily use that pulse generator with the Analog or RC pulse inputs.

  2. You only need to send RS-232 signals to the motor controller, you don’t have to return, receive, or acknowledge anything. Also, the SMC04 has a TTL level, not RS-232, serial output for error information (i.e. in feedback mode, how far away from the commanded speed/position is the motor). You SHOULD NOT hook this output up to an RS-232 device, as the voltages used in the RS-232 protocol are much higher than those used in TTL serial.

  3. Yes, you can daisy chain Pololu serial devices (i.e. put them in serial), and the Pololu serial command protocol is set up so that commands to different device addresses and types of devices don’t interfere with each other. The devices don’t even need to have different addresses so long as you realize that devices with the same address will all respond to commands sent with that address. The address of Pololu serial devices aren’t set by dip switches, but they can be reprogrammed with serial commands.

Hope that clears things up!


Thank you! :smiley: