Status Words - Omron C200HW-PRM21 Operation Manuals

Control and status area
Sync / Freeze control

5-3-2 Status words

64
The purpose of the control commands Sync and Freeze is to be able to
synchronise the outputs and inputs of the slaves.
The data exchange between the master and slaves is based upon the polling
technique. This means that the exchange of data between the slave and the
master does not occur at the same time for all slaves.
The outputs of the slaves can be synchronised by issuing Sync commands.
This function is activated after the first Sync command is sent to the slaves.
After activation of this function, the output data sent by the Master does not
get through to the output. It is stored in a buffer. The data in the buffer is not
transferred to the output until another Sync command is issued. Multicasting a
Sync command results in a update of the outputs of all corresponding slaves
at the same time. This function can be disabled again by sending an Unsync
command.
The Freeze and Unfreeze command work in a similar way. They are meant
for synchronising the input data. After activating the function, by sending a
Freeze command, the input data is not updated until another Freeze
command is sent.
The Unit provides 19 words of status information.
Three words (IR n+2 ~ IR n+4) show the status of the Unit (system status)
and 16 additional words show the status of all slaves. System status
information is transferred in each I/O refresh, irrespective of the state of the
fieldbus system. The slave status information is also always transferred, but is
not valid when the PROFIBUS-DP bus communication does not function
properly or during the download of a configuration. In that case the slave
status information bits will be reset to 0.
System status
The three words that indicate the system status are shown below.
15 14 13 12 11 10 9
IR n+2
8 7 6 5 4 3 2
DM setting error (exceeding max. words)
DM setting error (output area mapping)
DM setting error (input area mapping)
Section 5-3
1 0
Input data transferred
Auto_clear
P-DP H/W failure
Wrong CPU Unit
Control command not processed
Output mailbox full
Reply in input mailbox
Network state
No_data