Lust CM-CAN1, User Manual, Page: 44 / 84

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User Manual CM-CAN1
4 Setting the device parameters
For synchronization purposes the master requests each substring by
means of a request telegram. The drive unit copies the received telegram
to its transmit area, overwrites the telegram’s data area with the string
data and sends it back to the master. Data byte 7 (block counter) is incre-
mented by the master and by the slave on every partial transfer. The last-
but-one reply telegram from the drive unit contains the 0 terminator of the
string in its data area.
In the last reply telegram the drive unit enters the LIST_ End identifier in
the status byte. The data area of the telegram now contains the check-
sum covering all individual data areas (0 to number of blocks -1) of the
drive unit reply telegrams which have contained part of the data string.
If the string length is < 3, the second block is the last block and then
already contains the checksum.