Mapping

The KM2774 terminal module occupies input and output addresses in the controller's process image. The assignment of process data (input and output data) and parameterization data (control and status bytes) to the control addresses is called mapping. The type of mapping depends on:

the fieldbus system used
the terminal type
the parameterization of the Bus Coupler (conditions) such as
- compact or complex evaluation
- Intel or Motorola format
- word alignment switched on or off

The Bus Couplers (BKxxxx, LCxxxx) and Bus Terminal Controllers (BCxxxx, BXxxxx) are supplied with certain default settings. The default setting can be changed with the KS2000 configuration software or with a master configuration software (e.g. TwinCAT System Manager or ComProfibus).

The following tables show the mapping depending on different conditions. For information about the contents of the individual bytes please refer to the pages Process image and Control and status byte.

Compact evaluation

Under compact evaluation, the KM2774 occupies addresses in the input and output process image. Control and status bytes cannot be accessed.

Compact evaluation in Intel format

Default mapping for CANopen, CANCAL, DeviceNet, ControlNet, Modbus, RS232 and RS485 coupler

	Address	Input data		Output data
Conditions	Word offset	High byte	Low byte	High byte	Low byte
Complex evaluation: no Motorola format: no Word alignment: any	0	D1	D0	D1	D0

Compact evaluation in Motorola format

Default mapping for PROFIBUS and Interbus coupler

	Address	Input data		Output data
Conditions	Word offset	High byte	Low byte	High byte	Low byte
Complex evaluation: no Motorola format: yes Word alignment: any	0	D0	D1	D0	D1

Complex evaluation

Under compact evaluation, the KM2774 occupies addresses in the input and output process image. Control and status bytes can be accessed.

Complex evaluation in Intel format

	Address	Input data		Output data
Conditions	Word offset	High byte	Low byte	High byte	Low byte
Complex evaluation: yes Motorola format: no Word alignment: no	0	D0	SB	D0	CB
	1	-	D1	-	D1

Complex evaluation in Motorola format

	Address	Input data		Output data
Conditions	Word offset	High byte	Low byte	High byte	Low byte
Complex evaluation: yes Motorola format: yes Word alignment: no	0	D1	SB	D1	CB
	1	-	D0	-	D0

Complex evaluation in Intel format with word alignment

Default mapping for Lightbus, Ethernet and EtherCAT couplers (BK1120) and for Bus Terminal Controllers (BCxxxx, BXxxxx)

	Address	Input data		Output data
Conditions	Word offset	High byte	Low byte	High byte	Low byte
Complex evaluation: yes Motorola format: no Word alignment: yes	0	reserved	SB	reserved	CB
	1	D1	D0	D1	D0

Complex evaluation in Motorola format with word alignment

	Address	Input data		Output data
Conditions	Word offset	High byte	Low byte	High byte	Low byte
Complex evaluation: yes Motorola format: yes Word alignment: yes	0	reserved	SB	reserved	CB
	1	D0	D1	D0	D1

Key

Complex evaluation: In addition to the process data, the control and status bytes are also mapped into the address space.
Motorola format: Motorola or Intel format can be set.
Word alignment: In order for the channel address range to commence at a word boundary, empty bytes are inserted into the process image as appropriate.

SB status byte (appears in the input process image)
CB: Control byte (appears in the output process image)

D0: low-order byte of the data word
D1: high-order byte of the data word

reserved: This byte is assigned to the process data memory, although it has no function.
"-": This byte is not assigned or used by the module.