Helmholz 700-651-CAN01, Manual

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4.6.2 29-bit protocol
In order to receive any CAN frames with the Receive Object the
upper 26 bits of the CAN identifier are first filtered with a mask
(acceptance mask) and then compared with a predefined value
(acceptance code). If this comparison is positive, the CAN frame is
entered in the Receive FIFO and the PLC is released.
28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Received CAN identifier
AcceptanceMask (e.g. 11111111111110000000000000)
AcceptanceCode (e.g. 1111111111111111111011xxxx)
ignored
Acceptance Mask 11111111111111111111110000 (= 536870784)
filters out the top 26 bits. Acceptance code
1111111111111111111011xxxx (= 536870272) defines which
frames are to be accepted after filtering.
In this example it is the CAN frames with identifiers 0x1FFFD80
to 0x1FFFFDFF.
DP/CAN Coupler 19