Configuring Communications
The parameters that control the communication between a controller and an I/O module are described.
Variable Addressing Mode
Variable addressing mode is the default addressing mode of the I/O module, but it is not the default
mode for the function block.
When the device is powered, the CAN shield input voltage is measured. Communication parameters are
determined from the
I/O Module CAN Message Identifiers
table. For proper communication between the
function block and the I/O module, the corresponding N1 value from the table must be entered in the
function block and AddrMode must be set to 0.
Every time the device is powered, the CAN shield input voltage must be within the same N1 range for the
function block and device to reach the Configured status. After the device is powered, the CAN shield
input voltage has no effect on communication.
Predefined Addressing Mode
Predefined addressing mode is the default addressing mode for the function block, but it is not the
default mode for the I/O module.
In this mode, the I/O module reads the N1 value stored in non-volatile memory (EEPROM).
Because the function block and the I/O module use different default addressing modes, as long as the N1
value determined in the I/O module matches the N1 value set in the function block, the device is
configured using predefined addressing mode during all subsequent power cycles. As such, the proper
CAN shield voltage is only required during the first device initialization.
If setting the CAN shield voltage is not practical, use the PLUS+1
®
Service Tool to set the AddrMode to 1
and to set the required N1 value.
Fixed Addressing Mode
Fixed addressing mode allows for any pair of CAN message identifiers to be used for I/O module
communication.
In this mode, the I/O module relies on the RX_ID, TX_ID, and Frame parameters for communication with
the function block. Use the PLUS+1
®
Service Tool to set the proper values to match the function block and
to set the AddrMode.
Volatile Parameters
Once initial communication is established, all volatile parameter configuration messages are sent to the
I/O module.
User Manual
PLUS+1® Compliant IX012-010 Function Block
IX012-010 Function Block
©
Danfoss | July 2018
11063398 | AQ00000107en-US0101 | 9
