Functions
8.1 PROFIBUS DP
ET 200pro distributed I/O system
Operating Instructions, 03/2013, A5E00335544-08
179
Control interface PIQ (AB x to AB x+2):
The control interface is used to notify the IM154-1/-2 about the modules that are actually
present and which slots have been skipped. The IM154-1/-2 cannot evaluate the
configuration until it has received this information. Slot 0 (IM 154-1/-2) and slot 1 (virtual
power module PM-E) must be assigned the value 1.
Table 8- 1
Control interface
Slot
Value of the bit
Reaction
0 and 1
0
Content of the bit track is not relevant
1
Bit track is valid
2 to 17
0
Slot is not present in the actual configuration
1
Slot is present in the actual configuration
Feedback interface PII (EB x to EB x+2):
The feedback interface (3 bytes) tells you which module is actually located in a certain slot.
Table 8- 2
Feedback interface
Slot
Value of the bit
Reaction
0 and 1
0
Option handling is disabled
1
Option handling is enabled
2 to 17
0
Slot belongs to an option that not available or the module status
is not OK
1
Slot is available and is OK
If the feedback result of the feedback interface is identical with the specification of the control
interface, the configuration is correct.
Procedure
In order to start testing the options, set Bit 0=1 in the first byte (AB x).
Proceed as follows in order to ensure the consistency of the 3 bytes:
●
Write the first byte (AB x) last (for direct access with T PAB)
or
●
First write the complete information of the control interface in the first byte (AB x) with
Bit 0=0 and then set Bit 0=1 in this byte in the subsequent OB1 cycle.
Alternatively, you can use SFC15 in order to achieve consistent transfer.
Note
Whenever any change in the 3 bytes of the control interface takes place, this information is
stored and used, even if non-relevant bits were changed (bits outside the preset
configuration).