5 Help with problems
5.2 Troubleshooting
38
Version 04 05/2014
5.2.2 Systematic troubleshooting
This chapter helps you to localize an error systematically
with the help of the following questions.
See also the description of the LED displays in chap. 5.1,
page 35, and chapter 5.2.1.
Check the following points:
䊳
Are all the electrical bus lines terminated at both ends
in accordance with PROFIBUS specification (
even
for short electrical lines
)?
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Are the lengths of the optical cables within the thres-
hold values specified in this manual? (see chap. 7,
page 43)
䊳
Is the reception level of the optical channels within the
permissible range? (see chap. 7, page 43)
䊳
Are the DIL switches set according to the topology,
mode of operation, compatibility and optical transmis-
sion power? (see chap. 4.6, page 27)
䊳
Were the following points taken into account regar-
ding topology:
Line topology
- Line topology selected and set according to the
specifications in chapter 3.1 with or without F/O link
monitoring.
Star topology
- CH1 must be switched to “Monitor off” mode (S0=1)
for all OZD Profi 12M … PRO connected to the elec-
trical star segment.
- Wiring of the electrical star segment must be under-
taken with care.
- Expansion of the electrical star segment is to be as
small as possible.
- The electrical star segment must be terminated at
both ends.
- No bus subscribers are to be connected to the elec-
trical star segment.
- Non-busy optical channels are to be switched to
“Line without F/O link monitoring” operating mode.
Redundant optical ring
- Both channels of all the OZD Profi 12M … PRO
must be set to “Redundant optical ring” operating
mode.
- All the OZD Profi 12M … PRO within a ring must be
optically linked with one another.
䊳
Configuration (these settings can usually be set on the
PROFIBUS master using configuration software,
not
on the OZD Profi 12M … PRO):
- Slot time configured correctly? (for basics, see
chapter 3.2; for calculation, see “TSLOT.exe”)
- Retry value configured correctly? (target value >
_ 3,
see chapter 3.2)
- Value of MIN T
SDR
configured correctly? (target
value >
_ 11, see chapter, Retry)
- In case of redundant optical ring only:
“HSA” (Highest Station Address) configured correct-
ly or
“a non-existent bus subscriber” configured?
Note:
It may be necessary to perform a reset on the
device on which the parameters have been changed
(e.g. master) so that the new values can also be trans-
ferred!
䊳
Check the status of the LEDs and use chapter 5.1 and
5.2.1 to check the possible causes and resolve the
errors detected.