Control Techniques Mentor MP User Manual

Menu 3
Parameter
structure
Keypad and
display
Parameter x.00
Parameter description
format
Advanced parameter
descriptions
Serial comms
protocol
Performance
50 Mentor MP Advanced User Guide
www.controltechniques.com Issue Number: 4
These parameters effectively give the encoder position with a resolution of 1/2
16
ths of a revolution as a 32 bit number as shown below.
Provided the encoder setup parameters are correct, the position is always converted to units of 1/2
16
ths of a revolution, but some parts of the value
may not be relevant depending on the resolution of the feedback device. For example a 1024 line digital encoder produces 4096 counts per
revolution, and so the position is represented by the bits in the shaded area only.
When the encoder rotates by more than one revolution, the revolutions in Pr 3.28 increment or decrement in the form of a sixteen bit roll-over counter.
An incremental digital encoder may have a marker channel. When this channel becomes active it may be used to reset the encoder position and set
the marker flag (Pr 3.31 = 0), or just to set the marker flag (Pr 3.31 = 1). The marker flag is set each time the marker input becomes active, but it is not
reset by the drive, and so it must be cleared by the user.
If Pr 3.35 is set to zero the marker system operates in a conventional manner and only resets the position (Pr 3.29) and not the turns (Pr 3.28) on a
marker event. If Pr 3.35 is set to one the whole position (Pr 3.28 and Pr 3.29) are reset on a marker event. The full reset mode allows the marker to
give a form of registration where the marker event defines zero position.
This parameter has a different function depending on the type of encoder selected with Pr 3.38 and Pr 3.39.
It is sometimes desirable to mask off the most significant bits of the revolution counter of encoders. This does not have to be done for the drive to
function correctly. If Pr 3.33 is zero the revolution counter (Pr 3.28) is held at zero. If Pr 3.33 has any other value it defines the maximum number of
the revolution counter before it is reset to zero. For example, if Pr 3.33 = 5, then Pr 3.28 counts up to 31 before being reset.
3.29
Drive encoder position
Coding
Bit SP FI DE Txt VM DP ND RA NC NV PT US RW BU PS
11111
Range
0 to 65,535 (1/2
16
ths of a revolution)
Update rate 4 ms write
31 16 15 0
Revolutions Position
31 16 15 4 3 0
Revolutions
Position
3.31
Drive encoder marker position reset disable
Coding
Bit SP FI DE Txt VM DP ND RA NC NV PT US RW BU PS
111
Default 0
Update rate Background read
3.32
Drive encoder marker flag
Coding
Bit SP FI DE Txt VM DP ND RA NC NV PT US RW BU PS
111
Default 0
Update rate 250 μs write
3.33
Drive encoder turns bits
Coding
Bit SP FI DE Txt VM DP ND RA NC NV PT US RW BU PS
111
Range 0 to 16
Default 16
Update rate Background read (Only has any effect when the drive is disabled)

Control Techniques Mentor MP Specifications

General

Brand	Control Techniques
Model	Mentor MP
Category	DC Drives
Language	English