Omron FQM1-CM001, FQM1-MMA21, FQM1-MMP21 operation manual 208

Functions for Servo Drivers Compatible with Absolute Encoders Section 7-7

Step 3 (as Needed): Origin

Compensation (Absolute

Offset Preset)

Note

Note

Step 4 (Required):

Absolute Present Value

Preset

Step 5 (Required): Operating Command to Servo Driver

Step 6 (Required): Stopping Servo Driver

After a short time has passed to allow the Servo Driver's output to stabilize, turn ON the High-speed Counter Start Bit (A610.00) from the ladder program. The encoder's status (multi-turn data), which was acquired when the SEN sig- nal was turned ON, is received as serial data. After the multi-turn data has been received through serial communications, the Absolute Number of Rota- tions Read Completed Flag (A608.05) will go ON. If a reception error occurs at this point, the Absolute Number of Rotations Read Completed Flag (A608.05) and Absolute Number of Rotations Read Error Flag (A608.04) will go ON and the received data will be discarded.

When necessary, the absolute offset preset function can be used to set encoder's present position as the origin.

Use the absolute offset preset function to store the present value that will be defined as an origin as the absolute offset; the present value is computed from the Absolute Number of Rotations PV (A604 and A605) and the Number of Initial Incremental Pulses (A600 and A601).

To use the absolute offset preset function, turn ON the Absolute Offset Preset Bit (A610.05).

When performing origin compensation, set the absolute offset to 0 before starting the origin compensation operation. Use the CX-Programmer’s Sys- tem Setup to set the absolute offset to 0.

To use the absolute offset preset function, wait 30 to 62.5 ms after the Abso- lute Number of Rotations Read Completed Flag (A608.05) is turned ON and then toggle (turn ON and then OFF) the Absolute Offset Preset Bit (A610.05).

Be sure to perform the absolute offset preset operation before starting normal Servo Driver pulse outputs. The Absolute Offset Preset Bit’s ON timing depends on encoder's resolution, etc. Adjust as needed corresponding to the system.

Use the absolute present value preset function to store the absolute present value in high-speed counter PV 1 (A600 and A601).

To use the absolute present value preset function, toggle (turn ON and then OFF) the Absolute PV Preset Bit (A610.06).

Turn ON the RUN Signal Output Bit (Servo Lock). Doing so will cause the Servo Driver to start operating. At the same time, the Motion Control Module will start receiving pulse trains and counting the number of pulses corre- sponding to Servo Driver’s rotational displacement.

Turn OFF the RUN Signal Output Bit (Servo Lock). Doing so will stop the Servo Driver. In addition, turn OFF the Absolute Number of Rotations Read Bit (A610.07) and High-speed Counter Start Bit (A610.00). When these bits are OFF, the Motion Control Module will stop counting the pulse trains.

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