Trinamic 11-0011 TMCM-171 BLDC Output For 3-phase BLDC Motors 11-0011 Datenbogen

TMCM-171 Manual (V0.92 / Nov 7th, 2007) 

 

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Copyright © 2007, TRINAMIC Motion Control GmbH & Co. KG 

 

The TMCM-171 can use nearly any BLDC motor and encoder type. However, care has to be taken to 
correctly set the motor pole count (default: 8) and encoder resolution (default: 4096) and direction 
(default: Encoder gives same direction as motor) before trying to operate the motor! If a hall sensor is 
used, please check if the hall sensor polarity is to be reversed (try operating the motor in block 
commutation mode, first). Also choose a fitting initialization mode (2 is most universal) and set the 
corresponding parameters (please see chapter on start up). 
The motor behavior afterwards may still give unsatisfactory results: The next step is to tune the PID 
parameters. 
For these basic settings, the Windows based demonstration application can be used. It requires 
connection to the CAN or the RS485 interface. As a first step use the TMCL-IDE to set the parameter 
“Telegram pause time” to a value of about 20. Further basic settings are required for motor start up 
(see next chapter). 
 
Hint:  

 

The TMCM-171 uses an incremental encoder for motor commutation. Incremental means, that the 
encoder does not give an absolute position reference. Thus, the unit needs an internal start up 
procedure, which determines the encoder position with respect to the actual pole motor orientation.  
 
The TMCM-170 provides basically two modes for encoder initialization:  
Mode 0   uses additional motor hall sensors for the start up phase. Therefore, the motor can not do a 

precise positioning until it has done at least one electrical rotation. This can be perceived 
by a somehow rough behavior on the first positioning run. 
We recommend using this mode, when the motor has hall sensors and mode 1 does not 
give reliable results. 
However, the motor hall sensors typically are not as precise, as this would be desired for 
sine  commutation. To accomplish with the hall sensor error and hysteresis, you can set the 
corresponding parameters “Init Sine Block Offset CW” and CCW. 

 
Mode 1   drives the motor field into a known position and then evaluates the encoder position. 

While this is a very precise scheme, it is susceptible to external force applied to the rotor: 
The rotor is not to be blocked in any direction. Additionally external mechanical torque 
applied to the axis should be kept low. To use this mode, it is important to set the “Sine 
Initialization Current A” as high as possible (within the 20A limit). Default value is 10A. You 
can set Sine Initialization Current B to a somewhat lower value (at least ½ of Current A) to 
give optimum results. The best setting has do be determined for a given motor. To allow 
for minimum motor movement upon initialization, this mode also checks the hall sensor 
positions. 

 
Mode 2  is the same as mode 1, but does not check if the motor has hall sensors. 
 
Mode 3  is the most precise and reliable initialization mode: It uses the encoder N-channel for 

initialization. To first find the N-channel reference position, the motor is turned by up to 
one rotation, until the N-channel is found positive. The velocity and direction can be 
specified using the parameter “Sine Init Velocity”. After finding the reference position, the 
“Actual Commutation Offset” gives the angular relationship between motor and encoder.