profibus distance error

Hiii

Can u tell me what should the maximum length of the profibus cable to be used between the master and slaves.I have used the baud rate of 1.5 Mbps and i have the problem with this.I have set it to 187.5Kbps its ok.my distance from master to slave is less than 100 metres.can anybody tell me what will be the possibility of the error.

Shanmugam

100m should be fine for almost all baud rates, if you are using good quality cable (well, any actual ProfiBus cable), and have both ends properly terminated.

For a single master to slave, you need both ends terminated with a resistor.

Shanmu gam

What? You've already installed the network and now you ask about cable lengths, baud rates ... ?

Try http://www.profibus.com/pall/meta/downloads/article/00325/ and get the official Profibus Organisation Installation Guide. This current edition is coming up to 10 years old. It's not as if Profibus is new, emerging, hidden technology.

Ken

Missing termination.

Last node in the link is shutdown (no 5V for the termination). --> If this is not an abnormal situation, then install an "active terminator" as the last in the network cable.

Cables not proberly mounted in the connectors.

Excessive noise. --> Rearrange cable routes to separate Profibus cables from noisy cables. Or remove the source of the noise if possible.

Poor ground.