I have a very specific question on ASDA-B2 servo driver and I hope there is someone who has hands on experience with it who can help me out.

I have referred to this user manual and it is not very clear on position control. In Chapter 6 it describes the modes of operation. The P mode (External Position Control mode) description says that the position control is achieved using an external pulse command. Topic 6.2 describes this further.

I want the motor to be controlled using modbus via RS485 serial communication (so that I can directly control the motor by a PC). Does this mean I have to use an external pulse generator circuitry connected to the controller if I need position controlling?

From the manual - Page 116

Description on position control mode - Page 117

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    \$\begingroup\$ I’m voting to close this question because it is an off topic product usage question which has been long abandoned by the asker, already has an answer of sorts, and especially because its presence is attracting similar usage questions to be improperly posted in the answer box. \$\endgroup\$ Commented Oct 12, 2020 at 19:55

1 Answer 1


This kind of servo motor driver normally works together with a PLC. Of course, there would be many ways to generate the motion control signal you need, you can even do it with a bench function generator.

But I'm guessing your question is more from a user perspective, so if you want an out-of-the-box solution you should take a look at the range of PLCs offered by the manufacturer of your driver:


Most of them have both the pulse signal you need and RS485, Modbus or other communication options.

If what you meant is that you happen to have the driver seating there and you want to generate this position control signal as a DIY project with a microcontroller or Raspberry Pi; that's also quite feasible I think, but I would have to take a deeper look at the manual before jumping into conclusions.

Some of these devices even have a way to program particular motion control routines, see for instance here: https://www.youtube.com/watch?v=QJGwrEGMhjo but I'm not sure if your drive offers this and/or that would give you enough flexibility to produce the movements you need.

  • \$\begingroup\$ Thanks for the comment. As it turns out, the B2 model needs an external pulse train to operate in the position mode. Hence I have selected the A2 model which don't need an external pulse train \$\endgroup\$
    – doca
    Commented Jun 7, 2019 at 4:28

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