Balluff BIS M-4 045 0 07-S4 Series, Operating Manual

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60
Process data cycle:
A process data cycle consists of the complete sending of the input and output data. 10 or 32
bytes of input and output data plus 2 bytes of command data are transmitted.
Figure 35: IO-Link transmission sequence
1 The command is passed on to the IO-Link master by the controller via a bus system.
2 After the synchronization time t1 , the command is passed on to the BIS M-400-… via IO-Link. The
duration is dependent on the bus system, the master, the cycle time and the current state of the IO-
Link
communication (see problem described above).
3
The processing time begins with the arrival of the command at the M-400-… This is composed of the
time for the command processing t2 , the time for the actual read operation t3 and the evaluation time for
the read data t4 . A flat value of max. 3 ms can be estimated for t2 and t4 . The pure read time is calcula-
ted as described (see chapter 5.18 "Dynamic mode" on page 39) . Please note: If the data carrier that
is to be read was already detected by the device, the time for data carrier detection is eliminated.
4 The time for pure data carrier processing is shown here.
5 Following another synchronization time t5 , the first data is passed on to the IO-Link master with the next
input data cycle. In addition, the AE bit is set in the bit string. The time for this is t7 = 1 x cycle time.
6
The data is only passed on to the controller via the host bus system. The latency period
t6
is dependent
on the bus system and the IO-Link master.
7
After the first data arrives at the controller, the toggle bit in the output buffer must be inverted (see
chapter 9 "Output/input buffer" on page 48) . In the example, it is assumed that this occurs immedia-
tely and that the transfer to the IO-Link master happens fast enough that the BIS M-400-… receives the
new data on the next output data cycle.
8 Now, the device places the next and, thus, the last bytes of the read data in the input buffer and inverts
the toggle bit.
9 The controller retrieves the data and deletes the AV bit.
10 The re-updated output buffer is sent to the BIS M-400-…
11
The device ends the read command and deletes the bits in the bit string in the input buffer that belong to
the job.
9
Device Function
BIS M-4 _ _ IO-Link Device
Read/Write Device