Siemens TC12 Installation, Commissioning And Maintenance Handbook page 175

Set the Mode switch to the CONTROLLER position. (If the connection fault is lit
return the switch to OFF and check that the plugs are fully inserted before
proceeding).
Set up the required patterns for words 0 and 1 output to the desired 16 inputs of
the OTU. The OTU responds to the data and transmits reply bits back to the
Instation. The LED indicators on the OTS display the control data from the
Instation. The transmission confirm indicator should be ON. (The transmission
confirm switch is not used in this mode).
Repeat 5 as required.
If the transmission confirm indicator is not lit no data is transmitted from the
OTU.
5.3.3.2 Using the OTS to Check the Functioning of OTU PCB Inputs/Outputs
With the equipment set up as described above the operation of OTU
Inputs/Outputs can be checked:
Checking that OTU Outputs are working
Connect a handset to the OTU. Enter OTU handset commands to set the 16 OTU
outputs. Check that the appropriate LEDs display the status of the outputs as set
on the handset.
Checking that OTU Inputs are working
Enter OTU handset commands to display the status of the OTU inputs. Set
different patterns on the OTS data switches and check that these are correctly
displayed on the handset.
666/HE/43100/000
TC12 Installation, Commissioning & Maintenance Handbook
Page 165 Issue 10