Siemens SIMATIC NET PROFIBUS manual Operating mode Redundant optical ring

4 Setting Up 4.3 Setting compatibility, operating mode and transmitting power

Operating mode ”Redundant optical ring“

S7

S6

S5

S4

S3

S2

S1

S0

0 1

CH 3 CH 2

CH 3

CH 2

CH 1

CH3 is activated in this operating mode if S3 and S4 are in Position 1. CH2 is activated in this operating mode if S1 and S2 are in Position 1.

Note: This operating mode must always be set at both of the optical ports of

amodule.

4.3.3Reducing the optical transmitting power on the OLM/P11 and OLM/P12

Attention! The following details only apply for the S7 default position (S7 = 0)!

The OLM/P11 and OLM/P12 have a high level of optical transmitting power. Optical overloading may result if these modules are connected with non-OLM devices using plastic optical fiber cables, particularly if short cable lengths are used.

In this case the optical transmitting power can be reduced.

The DIL switch S5 is used to set the transmitting power of CH2.

The DIL switch S6 is used to set the transmitting power of CH3.

S6 does not have a function on the OLM/P11.

S7

S6

S5

S4

S3

S2

S1

S0

S7

S6

S5

S4

S3

S2

S1

S0

0 1

CH 3 CH 2

CH 3

CH 2

CH 1

0 1

CH 3 CH 2

CH 3

CH 2

CH 1

Leave S6 in Position 1 (default) if the optical fiber link to CH3 functions correctly in this position. Leave S5 in Position 1 (default) if the optical fiber link to CH2 functions correctly in this position.

Switch S6 to Position 0 (reduced) if overloading is detected at a non-OLM device when using plastic optical fiber cables to CH3.

Switch S5 to Position 0 (reduced) if overloading is detected at a non-OLM device when using plastic optical fiber cables to CH2.

Note:

The DIL switches S5 and S6 on the OLM for glass optical fiber cables do not have a function (the optical transmitting power cannot be reduced).

The transmitting power default setting (S5 or S6 in Position 1) must be set when using PCF fibers.

Version 1.0 8/00 19