Siemens SIMATIC S5 Manual page 25

Configuring with COM 115F
F1 Scanning or entering the subunit ID
The subunit ID of the connected PLC is read in online mode by pressing function key F1. The
value read is displayed in the status line, e.g.:
"SUBUNIT A"
if the subunits have not yet been defined, the following appears:
"SUBUNIT .."
After reading out, the cursor jumps to the output subunit ID. You can change this ID.
Entering the subunit ID
Switch on the power supplies for both subunits.
Connect the programmer to the subunit which is to be subunit A.
Press the F1 "Subunit" key and read the subunit ID.
Change the subunit ID if required by entering the letter A.
Confirm the entry with the <Enter> key.
Connect the programmer to the subunit which is to be subunit B.
Press the F1 "Subunit" key and read the subunit ID.
Change the subunit ID if required by entering the letter B.
Confirm the entry with the <Enter> key.
Switch both PS 931 power supplies off and on again.
Connect the programmer to subunit A after entering the subunit ID. Data traffic between the pro-
grammer and the S5-115F is only possible if both subunits have received the correct subunit ID.
Note
Each CPU 942-7UF13 has subunit ID B as supplied from the factory. If you have not
changed this ID in the CPUs, you need only enter ID A for subunit A.
1-12
"SUBUNIT NOT YET DEFINED".
S5-115F Manual
EWA 4NEB 811 6149-02