User manual
3U Servo Amplifier
Before testing any of Turbo PMAC’s software features for digital current loop and direct PWM interface,
it is important to know whether the hardware interface is working properly. PMAC’s M-Variables are
used to access the input and output registers directly. The examples shown here use the suggested M-
Variable definitions for Motor 1.
Purpose
The purpose of these tests is to confirm the basic operation of the hardware circuits on PMAC, in the
drive, and in the motor, and to check the proper interrelationships. Specifically:
Confirm operation of encoder inputs and decode •
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Confirm operation of PWM outputs
Confirm operation of ADC inputs
Confirm correlation between PWM outputs and ADC inputs
Determine proper current loop polarity
Confirm commutation cycle size
Determine proper commutation polarity
Preparation
First, define the M-Variables for the encoder counter, the three PWM output registers, the amplifier-
enable output bit, and the two ADC input registers. Using the suggested definitions for Motor 1, utilizing
Servo IC 0, Channel 1:
M101->X:$078001,0,24,S ; Channel 1 Encoder position register
M102->Y:$078002,8,16,S ; Channel 1 PWM Phase A command value
M104->Y:$078003,8,16,S ; Channel 1 PWM Phase B command value
M107->Y:$078004,8,16,S ; Channel 1 PWM Phase C command value
M105->Y:$078005,8,16,S ; Channel 1 Phase A ADC input value
M106->Y:$078006,8,16,S ; Channel 1 Phase B ADC input value
M114->X:$078005,14 ; Channel 1 Amp Enable command bit
Note:
The ADC values are declared as 16-bit variables even though typically, 12-bit
ADCs are used; this puts the scaling of the variable in the same units as Ixx69,
Ixx57, Ixx29, and Ixx79.
It is useful to monitor these values in the Watch window of the Executive program. Therefore, add the
variable names to the Watch window which causes the program to repeatedly query Turbo PMAC for the
values and display them. Then the hardware can be exercised with on-line commands issued through the
Terminal window.
To prepare Turbo PMAC for these tests:
1. Set I100 to 0 to deactivate the motor.
2. Set I101 to 0 to disable commutation (This allows for manual use of these registers.)
3. Make sure that I7000, I7004, I7016, and I7017 are set up properly to provide the PWM signals desired.
4. If the Amplifier Enable bit is 1, set it to zero with the command M114=0.
5. Set Ixx00 and Ixx01 for all other motors to zero.
Controller Setup 33