ICP DAS USA I-7530 User Manual page 25

Communication Descriptions:
When Device1 want to transmit RS-232 commands "1234567" to
Device2, the commands written to I-7530#1 by Device1 need to be
"0021234567" because the Device1 is set to dynamic Tx CAN ID (Fixed
Tx CAN ID is not checked). The first three bytes of "0021234567" is "002",
it means that the CAN ID is 0x002 when the I-7530#1 receives the RS-
232 commands from Device1 and transfers it to CAN message.
Afterwards, this CAN message is only accepted by Device2 because the
configurations of acceptance code and acceptance mask of Device2.
Similarly, if Device1 wants to send RS-232 commands "1234567" to
Device3, it needs to send "0031234567" RS-232 commands to I-7530#1.
When the Device2 or Device3 respond the RS-232 commands "456789",
the CAN message will have CAN ID "0x002" and "0x003" because of the
configurations of Fixed Tx CAN ID of I-7530#2 and I-7530#3. Because
the I-7530#1 is set to Response with CAN ID, the Device1 will receive the
RS-232 commands "002456789" or "003456789". Therefore, Device1 can
decide the target device which RS-232 commands will be sent to. Also,
Device1 knows where the RS-232 commands come from. The general
concept of transmitting data from Device1 to Device2 is shown below.
Note: In pair connection mode, all RS-232 commands listed in section 4
I-7530 RS-232/CAN Converter User's Manual (Version 2.2, June/2008) ------------- 25