Pepperl+Fuchs IDENTControl IC-KP-B5-V23 Manual page 24

IC-KP-B5-V23
Commands
Input data field (response):
Byte 0
Byte 1
Byte 2
Byte 3
Byte 4
...
Byte N (N is 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.
After the identification system processes commands, the "Status" is output in
accordance with the status/fault message table (see chapter 7.9).
The first byte of the response corresponds to the first byte of the command call-up
(command code).
The toggle bit of the response is the same as the toggle bit of the command.
If the status is FFh (command detected), the second byte of the response also
corresponds to the second byte of the command call-up. In the actual response
(status not FFh), the second byte contains the parameters for the response, i.e.
the number of words in the response and the channel used to transmit the
response. After a read command is issued, a response with the status 00 in the
"Word count" response parameter then contains the number of words in the
response telegram (which is also the command call-up). The number of words in
a response to a write command is 0000b because the response only contains the
status and not (useful) data. Here, the second byte of the response is not the
same as the second byte of the command call-up. With read only code
commands, the word count in the response is always 0000b. 3 responses are
issued for commands to all connected R/W heads (channel = 111b): The first
response (status = FFh) is followed up by 2 other responses that contain the
status of the individual channels. The "Channel" parameter in the response
telegram contains the number of the relevant channel (001, 010).
If new response data is available, the previous data is overwritten. The
configurable data hold time value defines the minimum duration that old data is
retained before it may be overwritten with new data. The default setting for the
timer value is 0.
New commands may only be issued to the device once the answer was retrieved
from the previously issued command.
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Command code (Echo)
Parameter/Toggle flag
Status
Reply counter
Read data
...
Read data