How to use an encoder
In fire protection engineering construction, coding alarm equipment is a fundamental task. Some people unfamiliar with fire protection installation engineering are confused about how to code equipment using encoders. This article provides you with the steps for coding fire protection equipment with encoders:
Applied to detectors and module encoders, it can set the address code, device type, and sensitivity of the detector; it can also set the address code, device type, input setting parameters, etc. of the module. After connecting the encoder to the detector or module bus and powering on, the following operations can be performed on the encoder to write and set the parameters.
( 1 ) Read code Press the read code key, and the address code of the detector or module will be displayed on the LCD screen; press the "increase" key, and for non-digital detectors or modules, the pulse width, year, batch number, sensitivity or module input parameters, and device type number will be displayed in sequence; for digital detectors or modules, the sensitivity level or module input parameters, device type number, and configuration information will be displayed in sequence (for digital temperature detectors, this item is the device subtype, 04 is a constant temperature detector, and 02 is an electronic differential constant temperature detector; for digital modules, this item indicates the shielded response parameter, 40 indicates shielded response, and the rest indicate no shielded response; this item is meaningless for other digital devices), press the "clear" key to clear.
( 2 ) Write the address code In standby mode, input the address code ( 1-242 ) of the detector or module, press the "encode" key, " p " is displayed if the encoding is successful, " E " is displayed if there is an error, press the "clear" key to return to standby mode.
( 3 ) Write the detector sensitivity or module input setting parameters. In standby mode, enter the unlock password and press the "clear" key. At this time, the lock has been opened. Press the "function" key and then press the number key " 3 ". The last digit on the screen will display a "-". Enter the corresponding sensitivity or setting parameters and press the "encode" key. The screen will display a " p " to indicate that the corresponding sensitivity or module input parameters have been written. Press the "clear" key to clear. Enter the lock password and press the "clear" key to return.
Of course, the fire alarm control panel of Xinwo on the market can encode smoke detectors, while smoke detectors of other brands such as Haiwan, Songjiang Yun'an, and Taihe'an must be encoded by an encoder and cannot be encoded by the fire alarm control panel.
Encoder debugging methods
After replacing a Siemens servo motor, the zero position needs to be adjusted. There's little difference between single-turn and multi-turn motors; essentially, it's about aligning the encoder's detection phase with the motor's electrical angle phase within one revolution. Early absolute encoders would provide the highest bit level of the single-turn phase on a separate pin. By toggling the 0 and 1 values of this level, encoder and motor phase alignment can also be achieved, as follows:
1. Apply a DC current less than the rated current to the UV windings of the motor using a DC power supply, with U as the input and V as the output, to orient the motor shaft to a balanced position ;
2. Observe the highest count bit level signal of the absolute encoder using an oscilloscope ;
3. Adjust the relative position of the encoder shaft and the motor shaft ;
4. While adjusting, observe the transition edge of the highest count signal until the transition edge accurately appears at the directional balance position of the motor shaft, then lock the relative position of the encoder and the motor ;
5. Twist the motor shaft back and forth. If the jump edge can be accurately reproduced each time the motor shaft freely returns to the balance position, then the zeroing is effective.
These types of absolute encoders have been widely replaced by newer absolute encoders using serial protocols such as EnDAT , BiSS , and Hyperface , as well as Japanese-specific serial protocols. Consequently, the highest bit signal no longer exists, and the method for aligning the encoder and motor phases has changed. One very practical method is to utilize the encoder's internal EEPROM to store the measured phase after the encoder is randomly installed on the motor shaft. The specific method is as follows:
1. Install the encoder randomly on the motor, that is, fix the encoder shaft to the motor shaft, and the encoder housing to the motor housing ;
2. Apply a DC current less than the rated current to the UV windings of the motor using a DC power supply, with U as the input and V as the output, to orient the motor shaft to a balanced position ;
3. Use a servo driver to read the single-turn position value of the absolute encoder and store it in the EEPROM inside the encoder that records the initial phase of the motor's electrical angle ;
4. The zeroing process is complete. Since the motor shaft is now oriented at -30 degrees of the electrical angle phase , the position detection value stored in the encoder's internal EEPROM corresponds to the -30 degree phase of the motor's electrical angle. Afterward, the driver subtracts this stored value from the single-turn position detection data at any given time, performs necessary conversions based on the number of motor pole pairs, and adds -30 degrees to obtain the motor's electrical angle phase at that moment.
