SJ700-2 Instruction Manual NT204DX - Hitachi America, Ltd.
SJ700-2 Instruction Manual NT204DX - Hitachi America, Ltd.
SJ700-2 Instruction Manual NT204DX - Hitachi America, Ltd.
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
Chapter 4 Explanation of Functions<br />
4.3.8 Motor gear ratio setting function<br />
The motor gear ratio setting function allows you to make the<br />
inverter effectively control a specific machine in which an encoder<br />
is installed at the opposite end of the motor.<br />
Specify the actual pulse count of the encoder as the encoder pulse-per-revolution (PPR) setting (P011).<br />
Specify the ratio of the motor speed to the encoder speed as the motor gear ratio (numerator "P028" and<br />
denominator "P029").<br />
According to the above settings, the encoder pulse-per-revolution (PPR) setting data converted into motor<br />
shaft data is set in the inverter.<br />
The encoder pulse-per-revolution (PPR) setting data converted into motor shaft data is used to detect<br />
speeds and positions. The data specified as the encoder pulse-per-revolution (PPR) setting (P011) is used<br />
to calculate the home search stop position.<br />
Item Function code Range of data Description<br />
Numerator of the motor gear ratio P028 0. to 9999<br />
Denominator of the motor gear ratio P029 0. to 9999<br />
Encoder pulse-per-revolution (PPR)<br />
setting<br />
P011<br />
128. to 9999., 1000 to 6553<br />
(10000 to 65530) (pulses)<br />
Note 1: The motor gear ratio (N/D) must be within the following range:<br />
1/50 ≤ N/D ≤ 20<br />
N: Numerator of the motor gear ratio<br />
D: Denominator of the motor gear ratio<br />
<br />
Related code<br />
P028: Numerator of the motor gear ratio<br />
P029: Denominator of the motor gear ratio<br />
P011: Encoder pulse-per-revolution (PPR)<br />
setting<br />
Setting of the ratio of motor<br />
speed to encoder speed<br />
Setting of the actual pulse<br />
count of encoder<br />
Encoder<br />
(1,024 pulses)<br />
Gear/load<br />
(1:10) Motor<br />
If the ratio of the motor speed to the encoder speed is 1:10, set the following data:<br />
Encoder pulse-per-revolution (PPR) setting (P011): 1024<br />
Numerator of the motor gear ratio (P028): 10<br />
Denominator of the motor gear ratio (P029): 100<br />
In this case, the periphery of the encoder shaft is divided into 4,096 sections to determine the points for<br />
home search. Note that the conceptual layout of the home search stop position is inverted from that shown<br />
in Figure 7-2.<br />
4.3.9 Position biasing function<br />
- The position biasing function allows you to make the position<br />
command bias during operation in pulse train position control<br />
Related code<br />
P024: Position bias quantity<br />
mode. This function adds the specified number of pulses to the variation of position data every 2 ms. Use<br />
this function to adjust the phase of the synchronization point during synchronous operation.<br />
- Specify the quantity to be added as the position bias quantity (P024).<br />
4.3.10 Speed biasing function<br />
Related code<br />
- This function allows you to make the speed command bias during A145: Additional-frequency setting<br />
A146: Additional-frequency sign selection<br />
operation in pulse train position control mode.<br />
- Specify the bias quantity for the additional-frequency setting (A145), and select a sign through<br />
additional-frequency sign selection (A146).<br />
- Assign function "50" (ADD) to an intelligent input terminal. The speed command is biased by the specified<br />
quantity while the ADD terminal is on.<br />
Speed biasing<br />
A145<br />
Position biasing<br />
P024<br />
ADD<br />
terminal<br />
Selected by A146<br />
Variation of position<br />
command<br />
Position control<br />
+/-<br />
Speed control<br />
Variation of position<br />
feedback data<br />
4 - 104<br />
Speed feedback data