Omron CQM1-ARM21, Руководство по эксплуатации

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AS-Interface Standard Modes
Section 4-4
33
4-4-3 I/O Data Bits
After the master has completed the initialisation, and has entered Normal
Operation, it will cyclically update each slave’s I/O data in the Input Data
Image and the Output Data Image.
The PLC CPU will access the master’s IDI and ODI during the PLC’s I/O
refresh, which takes place every PLC scan. The data in the IDI and ODI is
mapped to the I/O areas assigned to the CQM1-ARM21 as shown below.
Even if a slave has only outputs, its input data area will still be updated each
PLC cycle. The input data is copied straight from the slave reply. Check the
specifications of each slave to find out if any relevant information is returned.
The same is true for input-only slaves. Although in most cases the data sent
to input slaves will be irrelevant, slaves may interpret the data bits sent to it to
perform specific functions.
Inputs 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 IR bits
IR n Slave 3 Slave 2 Slave 1 Status Bits Inputs from slaves 1-3
IR n+1 Slave 7 Slave 6 Slave 5 Slave 4 Inputs from slaves 4-7
IR n+2 Slave 11 Slave 10 Slave 9 Slave 8 Inputs from slaves 8-11
IR n+3 Slave 15 Slave 14 Slave 13 Slave 12 Inputs from slaves 12-15
IR n+4
Slave 19 Slave 18 Slave 17 Slave 16 Inputs from slaves 16-19
IR n+5
Slave 23 Slave 22 Slave 21 Slave 20 Inputs from slaves 20-23
IR n+6
Slave 27 Slave 26 Slave 25 Slave 24 Inputs from slaves 24-27
IR n+7 Slave 31 Slave 30 Slave 29 Slave 28 Inputs from slaves 31-28
D3 D2 D1 D0 D3 D2 D1 D0 D3 D2 D1 D0 D3 D2 D1 D0 Data bits from slaves
Outputs 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 IR bits
IR m Slave 3 Slave 2 Slave 1 Command Bits Outputs to slaves 1-3
IR m+1 Slave 7 Slave 6 Slave 5 Slave 4 Outputs to slaves 4-7
IR m+2 Slave 11 Slave 10 Slave 9 Slave 8 Outputs to slaves 8-11
IR m+3 Slave 15 Slave 14 Slave 13 Slave 12 Outputs to slaves 12-15
IR m+4 Slave 19 Slave 18 Slave 17 Slave 16 Outputs to slaves 16-19
IR m+5
Slave 23 Slave 22 Slave 21 Slave 20 Outputs to slaves 20-23
IR m+6
Slave 27 Slave 26 Slave 25 Slave 24 Outputs to slaves 24-27
IR m+7 Slave 31 Slave 30 Slave 29 Slave 28 Outputs to slaves 31-28
D3 D2 D1 D0 D3 D2 D1 D0 D3 D2 D1 D0 D3 D2 D1 D0 Data bits to slaves
If the I/O range is restricted by the setting of the front panel DIP switches 1-3,
unused IR words can be allocated to other I/O units or used as work bits.
Note: The PLC scan cycle and the AS-Interface cycle are independent and
unsynchronised. Output data transferred to the CQM1-ARM21 in one PLC
scan can arrive at subsequent slave addresses with a delay of up to 5 ms (i.e.
the maximum AS-Interface cycle time). This depends on which slave has just
been serviced in the AS-Interface cycle. Data consistency is only guaranteed
within one slave’s data ’nibble’.