Standard Ramp Voltage; Deceleration Fail Detection Disable; Acceleration Rate Selector - Emerson Unidrive M200 Parameter Reference Manual

T = 2 √(Δw / J ) = 2 √(5.0 / 32.3) = 0.78s
SRamp1 Max
For RFC-A mode the general equations are used in the same way as for Open-loop mode. The required values are calculated as follows:
Δw = 1000 / ramp rate
a = 1000 / ramp rate
Max
J = 1000 / Max Rate Of Change Of Acceleration (02.007)
Max
Parameter

02.008 Standard Ramp Voltage

Short description Defines the standard ramp voltage used by the ramp system
Mode Open‑loop
Minimum −VM_DC_VOLTAGE_SET
Default See exceptions below
Type 16 Bit User Save
Display Format Standard
Coding RW, VM, RA
Voltage Region
110V All
200V All
400V 50Hz
400V 60Hz
575V All
690V All
See Ramp Mode Select (02.004).
Parameter

02.009 Deceleration Fail Detection Disable

Short description Set to 1 to disable the deceleration fail detection function
Mode Open‑loop
Minimum 0
Default 0
Type 1 Bit User Save
Display Format Standard
Coding RW
In the following circumstances it is possible that the motor may not decelerated or even accelerate.
1. When standard ramp is selected with a high inductance supply it is possible for the d.c. bus voltage to rise as the motor speed approaches
zero, and so the motor will continue to rotate slowly and not stop.
2. An overhauling load can cause the motor to accelerate.
It can be a problem if the drive state is changed to the "Decelerating" state and the motor does not stop. If Deceleration Fail Detection Disable
(02.009) is at its default value of 0, the motor frequency or speed is monitored in the "Decelerating" state, and if this does not fall over a period of 10s
the ramp output is forced to zero and the drive state is changed to "Stop" or "Inhibit" as appropriate.
If Deceleration Fail Detection Disable (02.009) = 1 this feature is disabled. This can be used in the following circumstances to prevent the system state
from changing from the "Decelerating" state before the motor has stopped:
1. If S ramps are being used with long ramp rates, and the motor is still accelerating when the drive is changed to the "Decelerating" state
because the run command is removed, then the ramp output may increase further before falling again towards zero.
2. The speed may appear not to reduce when very long ramp rates are used.
Parameter

02.010 Acceleration Rate Selector

Short description Defines which acceleration rate is used by the ramp system
Mode Open‑loop
Minimum 0
Default 0
Type 8 Bit User Save
Display Format Standard
Coding RW
The Acceleration Rate Selector (02.010) is used to either select an acceleration rate directly or to define the method used to select an acceleration rate.
If 1 ≤ Acceleration Rate Selector (02.010) ≤ 8 the acceleration rate is selected directly, i.e. 1 selects Acceleration Rate 1 (02.011), 2
selects Acceleration Rate 2 (02.012), etc. If Acceleration Rate Selector (02.010) = 0 the acceleration rate is selected with the acceleration rate select
bits as shown in the table below.
Unidrive M200 Parameter Reference Guide
Issue: 01.05.00.10
Maximum
Units
Update Rate
Decimal Places
Default Value
375
375
750
775
895
1075
Maximum
Units
Update Rate
Decimal Places
Maximum
Units
Update Rate
Decimal Places
VM_DC_VOLTAGE_SET
V
Background read
0
1
Background read
0
9
16ms
0
35