esd Protocol for CAN Modules - esd electronics, Inc.

3.3 Process TxIds
3 - 20
Commands and Parameters
By this command one or more Tx identifiers are allocated to the module, depending on the module
type, by which it is able to transmit the data onto the CAN (set TxIds).
The new Tx identifier replaces immediately after he had been received by the module the default
identifier adjusted by the coding switches. If the new Tx identifier should remain after a RESET or a
power-down, it has to be filed into the local EEPROM by command 'store parameter'.
Apart from that the module can be forced to transmit a reply about the Tx identifiers actually used
by it onto the CAN by the Tx identifier CTxId (request TxIds).
Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6
Function Command Sub command Not used Module no. Parameter 1 Parameter 2
Always
Request: $02
Selected
allocate with
Value $00...n module no.
$00
Set: $82
$01...$FF
Table 3.3.1: Bytes of the command set/request TxIds
CTxId
$0000...$07FF
TxId
$0000...$07FF
Command... By the command $02 the actual Tx identifiers are requested by the module.
After this request the module transmits the information on the identifier
'CTxId', entered into byte 5 and 6.
By the command $82 new Tx identifiers (TxId) to transmit I/O data are
allocated to the module corresponding to the sub command. The new Tx
identifiers are interchanged by byte 5 and 6.
Sub command... By the sub command it is selected which Tx identifier should be
interchanged. Depending on the module type a different number of Tx
identifiers can be set.
esd Protocol for CAN Modules Rev. 3.2