Why are there duplicated registers and which ones should I use?

The 0x6*** and the 0x2*** can be seen as duplicates with the only difference being the units. The 0x6*** are the registers as determined by the CANopen standard while the 0x2*** are our own OEM registers. For EtherCAT, you can use either of them as they are connected internally so the unit transformation will be done automatically.

Full information on these registers can be seen in the tables below.

Comparison Overview

CiA Registers	Acc	Type	Units	Manufacturer Registers	Acc	Type	Units	Conversion
0x6040 - Control Word	RW	UINT16	-	0x2010 - Control word	RW	UINT16	-	See: Control Word Conversion Table
0x6041 - Status Word	RO	UINT16	-	0x2011 - Status word	RO	UINT16	-	See: Status Word Conversion Table
0x605A - Quick stop option code	RW	INT16	-	0x260B - Quick stop option code	RW	INT16	-	No conversion.
0x605D - Halt option code	RW	INT16	-	0x2620 - Halt option code	RW	INT16	-	No conversion.
0x6060 - Operation mode	RW	INT8	-	0x2014 - Operation mode	RW	UINT16	-	See: Operation Mode Conversion Table
0x6061- Operation mode display	RO	INT8	-	0x2015 - Operation mode display	RO	UINT16	-	See: Operation Mode Conversion Table
0x6064 - Actual position	RO	INT32	Encoder counts	0x2030 - Actual position	RO	INT32	Encoder counts	No conversion.
0x6065 - Position following error window	RW	UINT32	Encoder units	0x21EC - Position following error window	RW	FLOAT	Encoder units	Type conversion.
0x6066 - Position following error timeout	RW	UINT16	ms	0x21ED - Position following error timeout	RW	UINT32	ms	Type conversion.
0x606C - Actual velocity	RO	INT32	mrev/s	0x2031 - Actual velocity	RO	FLOAT	rev/s	Unit conversion and Type conversion.
0x606F - Velocity threshold	RW	UINT16	mrev/s	0x21D6 - Velocity threshold	RW	FLOAT	rev/s	Unit conversion and Type conversion.
0x6070 - Velocity threshold time	RW	UINT16	ms	0x21D7 - Velocity threshold time	RW	UNIT32	ms	Type conversion.
0x6071 - Target torque	RW	INT16	‰ rated torque	0x2022 - Torque set-point	RW	FLOAT	Nm	Read 0x6076 - Motor rated torque to perform the conversion.
0x6073 - Max. current	RW	UINT16	‰ rated current	0x21E0 - Max. current	RW	FLOAT	A	Read 0x6075 - Motor rated current to perform the conversion.
0x6074 - Torque demand	RO	INT16	‰ rated torque	0x2053 - Torque demand	RO	FLOAT	Nm	Read 0x6076 - Motor rated torque to perform the conversion.
0x6075 - Motor rated current	RW	UINT32	mA	0x2100 - Rated current	RW	FLOAT	A	Unit conversion.
0x6076 - Motor rated torque	RW	UINT32	mNm	0x209A - Rated torque	RW	FLOAT	Nm	Unit conversion.
0x6077 - Torque actual value	RO	INT16	‰ rated torque	0x2029 - Actual torque	RO	FLOAT	Nm	Read 0x6076 - Motor rated torque to perform the conversion.
0x6078 - Current actual value	RO	INT16	‰ rated current	0x2076 - Current actual value	RO	FLOAT	A	Read 0x6075 - Motor rated current to perform the conversion.
0x607A - Position set-point	RW	INT32	Encoder counts	0x2020 - Position set-point	RW	INT32	Encoder counts	No conversion.
0x607B - Position range limit	RW	INT32	Encoder counts	0x21DE - Min position range limit	RW	INT32	Encoder counts	No conversion.
0x607B - Position range limit	RW	INT32	Encoder counts	0x21DF - Max position range limit	RW	INT32	Encoder counts	No conversion.
0x607C - Homing offset	RW	INT32	Encoder counts	0x2451 - Homing offset	RW	INT32	Encoder counts	No conversion.
0x607D - Software position limit	RW	INT32	Encoder counts	0x21EA - Min position	RW	INT32	Encoder counts	No conversion.
0x607D - Software position limit	RW	INT32	Encoder counts	0x21EB - Max position	RW	INT32	Encoder counts	No conversion.
0x6081 - Profile velocity	RW	UINT32	mrev/s	0x2025 - Profiler max. velocity	RW	FLOAT	rev/s	Unit conversion.
0x6083 - Profile acceleration	RW	UINT32	mrev/s²	0x2026 - Profiler max. acceleration	RW	FLOAT	rev/s²	Unit conversion.
0x6084 - Profile deceleration	RW	UINT32	mrev/s²	0x2027 - Profiler max. deceleration	RW	FLOAT	rev/s²	Unit conversion.
0x6098 - Homing method	RW	INT8	-	0x2450 - Homing mode	RW	UINT16	-	See: Homing Conversion Table
0x6099 - Homing search velocities	RW	UINT32	mrev/s	0x2453 - Homing limit search speed	RW	FLOAT	rev/s	Unit conversion.
0x6099 - Homing search velocities	RW	UINT32	mrev/s	0x2454 - Homing zero search speed	RW	FLOAT	rev/s	Unit conversion.
0x60B1 - Velocity loop input offset	RW	INT32	mrev/s	0x207B - Velocity loop input offset	RW	FLOAT	rev/s	Unit conversion.
0x60B2 - Torque offset	RW	INT32	‰ rated torque	0x2080 - Torque loop input offset	RW	FLOAT	Nm	Unit conversion.
0x60C2 - Interpolation time period	RW	UINT8	(10^itx) sec itx = interpolation time index	0x21EF - Interpolation time mantissa	RW	FLOAT	sec	Type conversion.
0x60C2 - Interpolation time period	RW	INT8	-	0x21F0 - Interpolation time exponent	RW	FLOAT	-	See Interpolation time exponent conversion table.
0x60F2 - Positioning option code	RW	UINT16	-	0x2024 - Positioning option code	RW	UINT16	-	No conversion.
0x60F4 - Position following error	RO	INT32	Encoder counts	0x21E2 - Position control loop error	RO	INT32	Encoder counts	No conversion.
0x60FF - Target Velocity	RW	INT32	mrev/s	0x2021 - Velocity set-point	RW	FLOAT	rev/s	Unit conversion and Type conversion.

Control Word Conversion Table

Bit	Mode	CiA Function	Manufacturer Function	Conversion
0	All modes	Switch On	Switch On	Identical value in both registers.
1	All modes	Enable Voltage	Enable Voltage	Identical value in both registers.
2	All modes	Quick Stop	Quick Stop	Identical value in both registers.
3	All modes	Enable Operation	Enable Operation	Identical value in both registers.
4	Profile position	Latch set-point	Run Set-Point Manager	CiA bit is written to Manufacturer bit 9.
	Homing	Homing operation start		CiA bit is written to Manufacturer bit 9.
	Other modes	Unused		Ignore
5	Profile position	Change immediately	Reserved	No dependency. A change in the CiA bit produces no changes in the Manufacturer register.
5	Other modes	Not specified	Reserved	Ignore
6	Profile position	Abs/Rel	Reserved	CiA bit is written to Manufacturer bit 11.
6	Other modes	Unused	Reserved	Ignore
7	All modes	Fault reset	Fault reset	Identical value in both registers.
8	All profiler modes	Halt	Halt	Identical value in both registers. Currently the halt bit has the same behavior in both registers.
8	Rest of modes	Halt	Unused
9	Profile position	Unused	New set-point	Manufacturer bit is written in CiA bit 4.
	Profile velocity		New set-point	Manufacturer bit is written in CiA bit 11.
	Homing		Homing operation start	Manufacturer bit is written in CiA bit 4.
	Rest of modes		Unused	Ignore
10	All modes	Reserved	Unused	Ignore
11	Profiler modes (including Profile Velocity)	Unused (Manuf. Spec)	Abs/Rel	Manufacturer bit is written to CiA bit 6.
	Profile Velocity	Latch set-point		CiA bit is written to Manufacturer bit 9.
	Rest of modes	Unused (Manuf. Spec)	Unused	Ignore
12	All modes	Manufacturer Specific	Unused	Ignore
13	All modes	Manufacturer Specific	Unused	Ignore
14	All modes	Manufacturer Specific	Unused	Ignore
15	All modes	Manufacturer Specific	Unused	Ignore

Status Word Conversion Table

Bit	Mode	CiA Function	Manufacturer Function	Conversion
0	All modes	Ready to switch on	Ready to switch on	Identical value in both registers.
1	All modes	Switched on	Switched on	Identical value in both registers.
2	All modes	Operation enabled	Operation enabled	Identical value in both registers.
3	All modes	Fault	Fault	Identical value in both registers.
4	All modes	Voltage enabled	Voltage enabled	Identical value in both registers.
5	All modes	Quick stop	Quick stop	Identical value in both registers.
6	All modes	Switch on disabled	Switch on disabled	Identical value in both registers.
7	All modes	Warning	Warning	Identical value in both registers.
8	All modes	Reserved	Reserved	Identical value in both registers.
9	All modes	Remote	Reserved	Ignore this field as it is not implemented
10	All modes	Target reached	Target reached	Identical value in both registers.
11	All modes	Internal limit active	Reserved
12	Homing	Homing attained	Homing attained	Identical value in both registers.
	CST, CSV, CSP	Drive follows the command value	Not used
	Profile position	Set-point ack.
	Profile velocity	Speed	Speed	Identical value in both registers.
13	Homing	Homing error	Homing error	Identical value in both registers.
	CST, CSV, CSP	Following error	Not used
	Profile position	Following error	Following error	Identical value in both registers.
	Profile velocity	Following error	Following error	Identical value in both registers.
14	All modes	Initial angle determination process finished	Commutation feedback aligned	Identical value in both registers.
15	All modes	Reserved	User bit

Operation Mode Conversion Table

Operation Mode	CiA Value	Manufacturer Value
Current Amplifier	-4	0x0001
Cyclic sync current mode	-3	0x0022
Current mode	-2	0x0002
Voltage mode	-1	0x0000
Profile position mode	1	0x0014
Profile velocity mode	3	0x0013
Homing mode	6	0x0113
Cyclic sync position mode	8	0x0024
Cyclic sync velocity mode	9	0x0023
Cyclic sync torque mode	10	0x0025
Profile position S-curve	-1	0x0044
Interpolated position	-1	0x00A4
Buffered PVT	-1	0x00B4
Position	-1	0x0004
Velocity	-1	0x0003
Torque	-1	0x0005

Writing "-1" to the CiA Register will always modify the Manufacturer Register value to "0x0001". On the other hand, writing values "0x0001", "0x0044", "0x00A4" and "0x00B4" to the Manufacturer Register, will always modify the CiA Register value to "-1".

This is why reading "-1" from the CiA Register, doesn't necessarily mean that the drive is in Voltage Mode.

Homing Conversion Table

Homing Mode	CiA Value	Manufacturer Value
No homing method assigned	0
Homing on the negative limit switch and index pulse	1	6
Homing on the positive limit switch and index pulse	2	5
Homing on the negative limit switch	17	2
Homing on the positive limit switch	18	1
Homing on negative index pulse	33	4
Homing on positive index pulse	34	3
Homing on current position	37	0

Interpolation time exponent conversion table

Int. Time exponent	CiA Value	Manufacturer Value
10^-5	-5	0.00001
10^-4	-4	0.0001
10^-3	-3	0.001
10^-2	-2	0.01
10^-1	-1	0.1
10^-0	0	1