Hi 

What is the difference between the Dark and Light Base units ? , I know that the light BU is used to enable a new potential group - but what does that mean (in real world) ? Can someone give an example of why we need a new potential Group ?

How do i select the Dark base ?  units right now i have a CPU 1512SP-1PN which is connected with 4 nos light base unit and 4 I/O modules and at the end is a server module . the CPU is working okay and i am able to download program but i need   to select 3 Dark base units  as the default configuration should be . How do i select the right one ? 

plc_317

Hi Pittiplatsch ,

What is the difference between the two types of the Base Unit , I am also using the 4 nos of Light colored Base unit and there is no problem I just need to select the light in the TIA portal . Do i need to use server module at the end (I am using one ) in both combinations all light or first light and the rest dark Base units .

What is the practical need of selecting a new potential group ?

hi plc_317,

I recommend you to have a look in the ET200SP-manual, Basic Information, ER200SP distributed I/O System, Chapter 3 .

SIMATIC ET 200SP Manual Collection

manual

Each BaseUnit BU...D that you install in the ET 200SP configuration opens a new potential
group and supplies all subsequent I/O modules (on BaseUnits BU...B) with the necessary
supply voltage. The first 24 V DC I/O module to the right of the CPU/interface module must
be installed on a light-colored BaseUnit BU...D.

...
If you want to place another BaseUnit BU...D after a BaseUnit BU...B, disconnect the power
and AUX buses and open a new potential group at the same time. This allows individual
grouping of the supply voltages.

You must feed the supply voltage L+ in via BaseUnit BU...D.
Each BaseUnit BU...B allows access to the supply voltage L+ via terminals (red/blue).

hope this helps,

regards,

Hello,

normally you use different potential groups if you use signals from different 24v Signal sources and no common 24v in the machine.

The type of BaseUnit you can configure in the TIA Portal, open the device view, select the IO-Slot and then in the properties select the type you need.

You can use whatever you want as base unit but you must configure it correctly.

Regards

Christoph

New question published by ducna is split to a separate thread with the subject I have a problem with the system of darkness as follows.

Best regards
The Helping Hand