TESTO 6681 Profibus Instruction Manual page 37

1.3.3.6 Manually set address
To ensure that the individual bus subscribers can be addressed directly by
the master, it is necessary that every bus subscriber is assigned a unique
address.
Important:
The address of a subscriber may only be assigned once!
Repeated assignment of an address leads to bus faults!
In the condition on delivery for the testo 6681 with Profibus
module, the switch setting FF is set.
If you wish to set the address using the Profibus
parameterization software, e.g. Siemens Simatic PDM (see
chapter 1.3.5.4, page 51), the default setting is required.
The manual setting of the address (hard address) overrides
the setting via the parameterization software (soft address).

The testo 6681 must be disconnected from the bus system.
1 Open transmitter (see Section Opening the instrument, chapter 1.3.3,
page 25).
testo 6681 Profibus
- 1.3 Commissioning 37