This command set mask to select CAN bus frames by their identifiers. Mask value has the same format of identifiers. Bits of mask value tell if identifier vs filter bits comparison must to be satisfied or not. If bit is set (1 = “care”) then the bit in the same position of identifier must match with the bit in same position of filter to be received (filtered-in). If the bit is reset (0 = “don't care”) then the comparision is always satisfied whatever is the value of the bit in the same position of identifier and filter.

CAN USER MASK CH<1/2> <standard part of ID>[:<extended part of ID>]

Return OK

Setting a mask to receive messages of which standard identifier bits all match with one filter from Channel #1:

CAN USER MASK CH1 FFE0
OK

Selecting x9xx range of identifiers from Channel #2:

CAN USER MASK CH2 0F00
OK
CAN USER FILTER CH2 0 0900
OK

1. Each channel has its own mask.
2. Sending the command <standard part of ID> and <extended part of ID> follow the alignment format currently selected. Please refer to CAN USER ALIGN command.
3. At power on reset all filters are disabled and values are cleared.
4. At power on reset mask value is 0, then setting a filter will result in receiving all messages.