QUESTION:
What is the effect of the ODIS signal (Output Disable) that can be set in the
DP1.INI or DP2.INI configuration file?

ANSWER:
a) ODIS = 0 (TELEPERM mode):
• The last values are held and issued to the DP slaves if the AS x88/TM is
placed in the STO state.
• The DP slaves do not hear about the STO state of the AS x88/TM.
The backup behavior in this mode must be checked for modules, DP slaves or
PA units with backup capability.

b) ODIS = 1 (PROFIBUS-DP mode):
• The ODIS signal is output cyclically to the DP slaves after the AS x88/TM has
transitioned to the STO state. The DP slaves assume the device-specifically
defined safe state. The safety value can either be hardwired at the unit or be
configured using COM PROFIBUS (hold last value or alternate value).
• The DP slaves hear about the STO state of the AS x88/TM.
• DP links to PROFIBUS-PA and AS-i transfer the ODIS signal to the
subordinate bus systems.
In STO state, DP master and all DP slaves remain active on the DP bus in either
mode. The DP slaves need therefore not have new parameter values assigned
upon a transition in the STA state.