ScanTool STN1100 FRPM - Manual (Page 17)

Family Reference and Programming Manual
STN1100FRPMA www.obdsol.com 17 of 23
of frame it is (single, first, consecutive, or flow control).
If the frame is not a valid ISO 15765-2 first frame, or
if flow control is off, it is passed to the block filters.
If the frame is a valid ISO 15765-2 first frame, and
flow control is on, what happens next is determined
by the ID type.
A 29-bit frame ID contains the address of the
transmitter, therefore a flow control frame is
transmitted for every ISO 15765-2 first frame, before
the frame is passed to the block filters.
An 11-bit frame is first compared to the list of flow
control 11-bit ID pairs. If a matching Rx ID is found, a
flow control frame is transmitted on the CAN bus using
the corresponding Tx ID. Otherwise, no flow control
frame is sent, and the received frame is passed directly
to the block filters.
By default, when an 11-bit CAN protocol is
selected, STN11xx defines the following flow control
11-bit ID pairs:
Tx ID Rx ID
7E0 7E8
7E1 7E9
7E2 7EA
7E3 7EB
7E4 7EC
7E5 7ED
7E6 7EE
7E7 7EF
Note that when adding custom flow control filters for
11-bit CAN messages using the STFAFC command, it
is important to add corresponding flow control 11-bit ID
pair (STFAFCP command) if the user wants to have
the flow control frames be sent.