Bosch Rexroth OptiFeed-FS EcoDrive 03 FLP04VRS - Page 343

ECODRIVE03-FL*-04VRS Command Communications 11-13
DOK-ECODR3-FL*-04VRS**-FK01-EN-P
Status Word Service Data
C E R L T Length Format
Data Data Data Data Data Data Data Data Data Data
S
0001000010101011 23 20 4E 30 30 30 30 20 4E 4F
#_N0000_NO
Fig. 11-22: "Read Response" From the Slave (First Fragment)
Now, the master must switch the toggle bit to show the slave that it is
ready to receive new data. The R/W-Bit, the L-Bit, the length and the data
are not of interest, and are therefore not considered by the slave.
However, the master should set the bits as shown below.
Control Word Service Data
C E R L T Length Format
Data Data Data Data Data Data Data Data Data Data
M
0001010100001011 x xxxxxxxxx
Fig. 11-23: The Master Sends a "Read Request" for the Second Fragment
The slave responds with the second fragment, which contains the
remaining 4 bytes. The L-Bit is set, because the system is processing the
last fragment. In addition, the length is set accordingly.
Status Word Service Data
C E R L T Length Format
Data Data Data Data Data Data Data Data Data Data
S
0001010101001011 50 20 20 20 x x x x x x
P___
Fig. 11-24: "Read Response" From the Slave (Last Fragment)
Writing a Value
In this example, an NC instruction is written:
• # N0000 NOP
The master clears the R-Bit to signal a write operation. In this example,
the length of the operating datum is 12 bytes. Because only 5 data words
are available in the Service Data Channel, the request cannot be sent all
at once, but must be fragmented. Therefore, the L-Bit is not set; the
toggle bit was switched opposite of the previous state.
Control Word Service Data
C E R L T Length Format
Data Data Data Data Data Data Data Data Data Data
M
0000000110101011 23 20 4E 30 30 30 30 20 4E 4F
#_N0000_NO
Fig. 11-25: "Write Request" From the Master (First Fragment)