Servo Motor Overtravel Settings Related to Basic Functions
In our previous article in our article series, which includes the basic functions that need to be done before starting the servo motor, we wrote “Basic Functions That Must Be Set Before Starting the Servo Motor”. In this article, we have brought together over-travel settings and other adjustments for you, as a continuation of the basic functions.Servo Motor Overtravel Related Settings
When excessive movement occurs during servo motor operation, the servo The servo motor function is defined as forcing the servo motor to stop in response to a signal input from the limit switch that is activated when the moving part of the motor exceeds the safe range of movement.Overtravel signals include P-OT (Forward Drive Prohibit) and N-OT (Reserve Drive Prohibit) signals.
Use P-OT and N-OT signals to stop the machine by installing the limit switch. The positions you want to stop the machine driven by the servo motor are given in the servo cable connection example below.
Overtravel signals include P-OT and N-OT signals.
Overaction Signals
Overtravel signals include P-OT and N-OT signals.
Brake hold is used to hold the position of the moving part of the machine when the servo motor is turned off, so that the moving part does not move due to gravity or an external force.
You can use the brakes on the servo motor or obtain brakes. The holding brake is used in the following situations.
Brake Operation Sequence
You must consider the time required for the brake to release and the time required for the brake to release to determine the timing of brake operation, as explained below.
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/BK (Brake) Signal
When the Servo Motor is Stopped /BK (Brake) Signal Output Timing
When the servo motor is stopped, the /S-ON signal turns OFF and the /BK signal becomes OFF at the same time. You should use the servo motor OFF delay time (Pn506) to change the timing of turning off the power supply to the motor after the /S-ON signal is OFF.
/BK (Brake) Signal Output Timing While Servo Motor is Running
If an alarm occurs while the servo motor is running, the servo motor will stop itself and /BK (Brake) signal output will start by setting the brake reference output speed level. (Rotary servo motors: Pn507, Linear servo motors: Pn583) and Ending the servo motor closing brake command waiting time. (Pn508)
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Electronic Gear Settings
The minimum unit of position data used to transport a load is called the reference unit. The unit of reference is used to give quantities of motion, not pulses, that are easier to understand over long distances or in other physical units (e.g. y̅̅m or 0).
Electronic gear is used to convert the movement distances specified in reference units into the pulses required for actual movements.
A reference unit with electronic gear servo package is equal to the workpiece movement distance per reference pulse input. In other words, if you use the servo pack electronic gear, the pulses can be read as reference units.
Note 1:If you install an electronic gear on the host controller, normally set the electronic gear ratio in the servo package to 1:1.
Note 2: If you enable reference pulse input multiplication switching, the reference unit is defined as position data equal to n times the reference pulses input from the main controller. ("n" is the reference pulse input multiplier.)
The difference between using and not using the electronic gearbox is shown below.
Absolute Servo Motor
In this example, the following machine configuration is used to move the workpiece by 10 mm.
Electronic Gear Ratio Settings
Adjust the electronic gear ratio using Pn20E and Pn210.
Electronic Gear Ratio Adjustment Examples
This section includes electronic gear adjustment examples.
Resetting the Absolute Encoder
In a system using an absolute encoder, multitype data must be initialized. Alarm related to absolute encoder (A.810 or A.820), absolute encoder must be reset. For example, when the power supply is on.
When you reset the absolute encoder, the multipath data is reset and absolute encoder related alarms are cleared.
Reset the absolute encoder in the following cases.
When starting the system for the first time
When alarm A.810 (Encoder Backup Alarm) is generated
When alarm A.820 (Encoder Checksum Alarm) is generated
When you want to reset multi-turn data in the absolute encoder
WARNING!
When the absolute value encoder is reset, multi-turn data is reset to a value between -2 and +2 turns. The reference position of the machine system changes. Set the reference position on the host controller to the position resulting from the absolute encoder reset. If the machine is started without setting the position on the host controller, personal injury or damage to the machine may occur due to unexpected starting.
INFORMATION
In the following cases multispecies data will always be zero. In such cases it is absolutely not necessary to reset the absolute encoder.
Reset Precautions
You cannot use the /ALM-RST (Alarm Reset) signal from the servo box to clear alarm A.810 (Encoder Backup Alarm) or alarm A.820 (Encoder Checksum Alarm). You can use the absolute encoder operation to clear these alarms.
If an A.8** occurs, turn off the power supply to reset the alarm.
Preparations
You should always check the following before performing an absolute encoder reset.
Parameter writing should not be prohibited.
The servo should not be turned off.
Applicable Vehicles
We shared with you the basic functions that need to be done before servo motor operation. You can get support from Şahin Rulman for any problems you experience during the adjustments. You can learn and buy servo motor prices online via Şahin Rulman website.
