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VUNIT Parameter (S300-S700)

ASCII - Command VUNIT    
Syntax Transmit VUNIT [Data]    
Syntax Receive VUNIT <Data>   Available in  
Type Variable rw   MMI No
ASCII Format Integer32   CANBus Object Number 365F (hex)
DIM -   PROFIBUS PNU 1951 (dec) IND = 1 (dec)
Range 0 .. 8   DPR 351 (dec)
Default 0    
Opmode All   Data Type Bus/DPR Integer32
Drive State Disabled + Reset (Coldstart)   Weighting  
Start Firmware 1.0    
Configuration Yes   Last Change of this Object 1.0
Function Group digital I/O   EEPROM Yes
Short Description System wide Definition of Velocity / Speed

Description

VUNIT gives the systemwide definition of velocity / speed resolution. This parameter effects all parameters that are related to velocity of the velocity controller and speed of the position controller.

VUNIT = 0 gives velocity in RPM (example OPMODE = 0)
gives speed in µm/sec (example OPMODE = 8). 
VUNIT = 1 Unit = RPM
VUNIT = 2 Unit = Rad/Sec
VUNIT = 3 Unit = Degree/Sec
VUNIT = 4 Unit = increments in PRBASE-format / 250µs

example: PRBASE = 24
1500U/min = 25U/s = 25*2^24/4000 IncrPRBASE / 250µs = 104857 IncrPRBASE / 250µs

VUNIT = 5 Unit = PUNIT / Sec
VUNIT = 6 Unit = PUNIT / Min
VUNIT = 7 Unit = 1000 * PUNIT / Sec
VUNIT = 8 Unit = 1000 * PUNIT / Min

Remark:
1. All parameters that are related to velovity have a fixed format of 32 Bit with 3 fractional digits. This causes a problem with some of the VUNIT settings (especially VUNIT=6), related to the resolution of the position controller (PGEARI), that not the full range of speed can be used. Under this condition, a different setting of VUNIT is necessary.

2. All parameters that are related to speed have a fixed format of 32 Bit with no fractional digits. This causes a problem with some of the VUNIT settings (especially VUNIT=3) to give fractional digits. Under this condition, a different setting of VUNIT is necessary.

Definition of the Calculation factors

VUNIT=1 1 UPM = 1048576*32/(4000*60) =~ 139.8 Counts
VUNIT=2 1 Rad/sec = 1048576*32/(4000*2*PI) =~ 1335 Counts
VUNIT=3 1 Grad/sec = 1048576*32/(4000*360) =~ 23.3 Counts
VUNIT=4 1 Counts/250µs = 32 Counts
VUNIT=5 1 PUNIT / sec = PGEARO / (125 *PGEARI)
VUNIT=6 1 PUNIT / min = (PGEARO * 60) / (125 *PGEARI)
VUNIT=7 1000 PUNIT / sec = PGEARO / (125 * PGEARI * 1000)
VUNIT=8 1000 PUNIT / min = (PGEARO * 60) / (125 * PGEARI * 1000)