FB#.RES

Description

FB#.RES reports the actual encoder resolution of the feedback deviceClosed A process whereby some proportion of the output signal of a system is passed (fed back) to the input. In automation, a device coupled to each motor to provide indication of the motor's shaft angle, for use in commutating the motor and controlling its speed and position. The drive calculates its value based on the encoder characteristics. It is provided in encoder counts/rev for rotary encoders and encoder counts/mm for linear encoders.

For digital-only feedbacks like incremental and HiperfaceDSL, the resolution will either be what the encoder indicates it supports or the resolution configured in the drive with FB#.ENCLINES or FB#.LINEPITCH. For feedbacks with an analog component (i.e. Sin/Cos, resolver, EnDat, etc.) the resolution will be the analog resolution including the drive’s 24-bit A/D conversion to indicate the higher resolution available.

FB#.RES is not the number of counts per revolution or pole pair for the position reported by FB#.P. FB#.PRES shows the resolution of FB#.P.

Examples

  • Sin/Cos rotary configured with 1024 lines/rev in FB#.ENCLINES:

    FB#.RES equals 1024 Periods over Rev multiplied by 2 to the 24th power Counts over Period is equal to 17,179,869,184 End Cnts per Rev

  • HiperfaceDSL rotary with 18 bits single turn + 12 bits multiturn:

    FB#.RES equals 2 to the 18th power which equals 262, 144 Enc Cnts per Rev

  • EnDat Analog linear with 20,000 nm/line

    2 squared 24 counts divided by period divided by 20 comma 000 nm divided by period times 1 million nm divided by 1 mm equals 838 comma 860 comma 800 Enc Cnts divided by mm

Versions

Action Version Notes
Implemented 02-00-00-000

General Information

Type

Read Only

Units

Rotary: Enc Cnts/revolution

Linear: Enc Cnts/mm

Range

N/A

Default Value

N/A

Data Type

Integer

Stored in Non-Volatile Memory

No

Variants Supported

All variants are supported.