Menu 7: Analog I/O - Control Techniques Digitax ST Advanced User's Manual

Parameter Keypad and
Parameter x.00
structure display
5.9

Menu 7: Analog I/O

Hardware
The drive has three analog inputs (AI1 to AI3) and two analog outputs (AO1 and AO2). Each input has a similar parameter structure and each output
has a similar parameter structure. The nominal full scale level for inputs in voltage mode is 9.8V. This ensures that when the input is driven from a
voltage produced from the drive's own 10V supply, the input can reach full scale.
Terminal Input
5/6 AI1
7 AI2
8 AI3
Terminal Output
9 AO1
10 AO2
Update rate
The analog inputs are sampled every 4ms except where the destinations shown in the table below are chosen, the input is in voltage mode and other
conditions necessary for short cutting are met.
Input destination
Pr 1.36 - Analog reference
Pr 1.37 - Analog reference
Pr 3.22 - Hard speed reference
Pr 4.08 - Torque reference
Analog outputs are updated every 4ms except when the source is Pr 3.02, Pr 4.02, Pr 4.17 and Pr 5.03 and high speed update mode is selected. In
high speed mode the output operates in voltage mode. It is updated every 250μs and special scaling is used as described in the table. User scaling is
ignored.
Output source
Pr 3.02 – speed
Pr 4.02 - torque prod current
Pr 4.17 - magnetising current
Pr 5.03 - output power
Digitax ST Advanced User Guide
Issue Number: 1
Parameter
description format
Input modes
Voltage only
(16 bit plus sign as a speed reference)
0 to 6
0 to 9
Output modes Resolution
0 to 3 10 bit plus sign
0 to 3 10 bit plus sign
Sample rate
250μs
(AI1 subject to window filter. See Pr 7.26 on page 105)
250μs
(AI1 subject to window filter. See Pr 7.26 on page 105)
250μs
(AI1 subject to window filter. See Pr 7.26 on page 105)
AI1 – 4ms
AI2 or 3 – 250μs
10.0V = SPEED_MAX
10.0V = Kc / 0.45
where Kc is the current scaling factor for the drive
10.0V = Kc / 0.45
The output is the product of the active current and the voltage component in phase
with the active current (vsy x isy).
10V would be produced when:
Active current = Kc / 0.45
Peak phase voltage in phase with the active current = DC_VOLTAGE_MAX / 2
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Advanced parameter Serial comms
descriptions protocol
Resolution
12 bit plus sign
10 bit plus sign
10 bit plus sign
Scaling
Electronic
Performance
nameplate
Menu 7
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