YSI IQ S ENSOR N ET Field bus linking - Manual (Page 16)

Configuring the IQ S ENSOR N ET IQ S ENSOR N ET Field bus linking
14 ba76148e01 06/2013
3.3 PROFIBUS / Modbus RTU checklist
The following checklist supports you when planning, projecting and
installing a PROFIBUS or Modbus RTU system with the
IQ S
ENSOR N ET . For smooth operation, you should be able to answer
all questions with "Yes".

Is the [bus system] (bus segment) installed without branch lines?
 Was the correct cable used (e.g. PROFIBUS cable, see section
2.1)?
 Are the poles of the signal lines A line and B line correctly connected
at all bus connections?
 Is it guaranteed that there is no short-circuit between A line, B line
and cable shielding?
 Is the shielding installed free of interruptions?
 Are the guidelines for shielding and grounding being observed, and
doesn't any unallowed potential equalization current flow via the
shielding?
 Is the maximum cable length (per bus segment) observed for the
corresponding baud rate?
 Do all devices support the required baud rate?
 Only for Profibus:
With 12 Mbit/s transmission rate only: Are the bus plugs suitable for
this baud rate?
 Are exactly two terminators switched on at the ends of the [bus sys-
tem] (bus segment)?
 Are the terminators supplied with voltage so the following applies:
U
B line
- U
A line
> + 500 mV?
 Do all devices have individual bus addresses?
 After changing the bus address, have the devices been restarted
(switched off and on again)?
Note: The IQ S
ENSOR
N
ET
does not have to be restarted.
 Do the addresses projected in the master correspond to the actual
addresses?
Are all addresses less than or equal to the parameter
HSA and less than 126 (HSA = Highest Station Address)?
 Only for Profibus:
Is the currently valid GSD being used? If you are in doubt, download
it from the Internet.
 Only for Profibus:
Have admissible bus parameters been set only? If you are in doubt
set them to default values.