Bosch Rexroth OptiFeed-FS EcoDrive 03 FLP04VRS - Page 342

11-12 Command Communications ECODRIVE03-FL*-04VRS
DOK-ECODR3-FL*-04VRS**-FK01-EN-P
Reading a Value
The master clears the R-Bit to signal a request. In this example, an NC
instruction is read out. The length of the control word is set to 8, which
indicates the valid length of the data in bytes, not counting the control
word. The toggle bit is set to 1, assuming it was set to 0 before. The L-Bit
is also set, because all the data is sent in one block and therefore, the last
fragment is transmitted.
Control Word Service Data
C E R L T Length Format
Data Data Data Data Data Data Data Data Data Data
M
0000010110001011 3F 20 4E 30 30 30 30 20 x x
?_N0000_
Fig. 11-19: The Master Sends a "Write Request"
The slave responds with a "Write Response" that contains no data.
Status Word Service Data
C E R L T Length Format
Data Data Data Data Data Data Data Data Data Data
S
0000010100001011 x xxxxxxxxx
Fig. 11-20: The Slave Sends a "Write Response"
The master now wants to read out the requested datum with a "Read
Request."
Control Word Service Data
C E R L T Length Format
Data Data Data Data Data Data Data Data Data Data
M
0001010000001011 x xxxxxxxxx
Fig. 11-21: The Master Sends a "Read Request"
The slave responds with a "Read Response," which contains the
requested data (total length = 14 bytes). The length indication was set to
10 and the toggle bit was also set to 1. The L-Bit is not set, because the
data is fragmented and cannot all be transmitted at once. An additional
fragment is required to receive the rest of the data.