Terminator on PROFIBUS network!

Field Network Q&A

Why do we need a terminator in our PROFIBUS network? What would happen if we left it out?

Expert’s answer: Terminator on PROFIBUS network

Leave it out, and you’ll hear, “I’ll be back!” Seriously, if you want your system to work right, then you need the terminator on PROFIBUS network. You may even need a whole series of them.

So every PROFIBUS network runs at high frequencies, using a copper medium called RS485. Every segment of this copper cable needs a terminating resistor at each end to absorb signal reflections. See, those reflections can corrupt PROFIBUS messages and cause network trips. Trip the network often enough, and it’ll eventually get mad and start tripping you. Let’s not go there, shall we?

Terminator on PROFIBUS network
Active DP Terminator T1 – Courtesy of PROCENTEC

A terminator basically consists of three resistor circuits that match the impedance of the PROFIBUS cables. You can use passive or active terminators, but active terminators will make your network more robust. And let’s admit it, they’re more badass. Hasta la vista, baby!

The following links have more about PROFIBUS:

Other resources that might interest you

PROFIBUS DP/PA remote configuration
Is it possible to bypass a PLC with remote access if you have a PROFIBUS network?

FOUNDATION Fieldbus architecture
What type of architecture can you build in an FOUNDATION Fieldbus system?

PROFIBUS grounding?
Why don’t PROFIBUS network cables have a signal in ground wires?

Related tags: PROFIBUS association profibus cables Profibus DP Profibus PA terminator
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