Pepperl+Fuchs IDENT-I system P IPT FP Series Manual page 20

IPT*-FP WITH U-P6-B5-V
Operation on the INTERBUS
Input data field:
Byte 0
Byte 1
Byte 2
Byte 3
Byte 4
...
Byte N
(defined by module selection)
In order to send a new command to the device, the INTERBUS master must write a command
in the output data field. The new command is executed when the data has changed relative to
the last read-in. If the same command is to be executed a number of times, the toggle flag must
be inverted, so that the device recognizes that a new command has to be processed.
Upon detection of a new command "Status" is set to FFh. In addition, the execution counter is
set to 00h and on every further execution of this command it counts up. If the execution counter
overruns, it starts again at 00h. An overrun exists when the execution counter reading is equal
to 00h and the status is not equal to FFh.
After the processing of commands by the identification system, the "Status" is output in
accordance with the Status/Fault signal table (see Section 7.8).
The first two bytes of the response correspond to the first two bytes of the command call-up.
Correspondingly, the toggle bit of the response is the same as the toggle bit of the command.
The commands buffered... and enhanced buffered... are executed repeatedly as long as the
commands remain in the output data field. The execution is terminated when a new command
is written in the data.
20
Command code (Echo)
Parameter/Toggle flag (Echo)
Status
Execution counter
Read data
...
Read data