Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Fan control

Fan control

Fan control


We're installing some vent fans in building A and want to be able to control them manually from building B. The control requirements are simply on/off/reverse. The two buildings are about 1km apart. There is a fiber optic communication backbone between both buildings.

After some research, I am thinking of doing the following:
  • Use fan soft starters in Bldg A containing a module that supports MODBUS TCP. Through this fieldbus, it's possible to start and stop the motor, read out currents and frequency, achieve info about warnings, faults, etc.
  • Use a desktop PC in bldg B running Wonderware HMI software, which will send MODBUS TCP commands to the softstarters
  • Use switches to convert from Ethernet to fiber (bldg B), fiber to Ethernet (bldg A) and then route the signal to individual starters.
  • Note: No PLC is used
My questions are:
  1. Will this work?
  2. Are there other alternatives I should look at?
  3. Would I be able to remotely login to the desktop PC to monitor and control the fans from another location if needed?

RE: Fan control

  1. Yes, it can be made to work. Whether it meets applicable codes regarding emergency stops and so on is more open to question.
  2. You mentioned one option - a PLC and either an MMI or PC. You can get safety-qualified PLCs with redundancy if that is a requirement. Most BMS hardware is capable of this functionality too.
  3. Given network access, yes you could. Whether you would want to is a different question given the potential for security problems.

RE: Fan control

Scotty - thanks for the quality answers.
1. We will have local disconnects/hand off autos at the fans for emergency stop
2. I was planning on using just a PC with Wonderware. For redundancy, we will have a spare PC.
3. Re: security, I will check with our IT dept about using an ACL, firewall and/or encryption. Thoughts welcome.


Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close