plc:plc_modbus_api
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plc:plc_modbus_api [2019/10/22 09:43] ivan |
plc:plc_modbus_api [2020/07/03 11:27] (current) ivan |
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| ===== PLC/Modbus API ===== | ===== PLC/Modbus API ===== | ||
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| A number of Variables from [[mycnc:global_variables|Global Variable Array]] are mapped to Modbus interface. It's possible to setup Modbus device ID, communication parameters and speed, and access to device Modbus Registers by writing to this variables. | A number of Variables from [[mycnc:global_variables|Global Variable Array]] are mapped to Modbus interface. It's possible to setup Modbus device ID, communication parameters and speed, and access to device Modbus Registers by writing to this variables. | ||
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| | 60030 | **Write Register**. Writing to register will send value from shadow register to Modbus devive to address given in written value on **write** operation | 16 | | | 60030 | **Write Register**. Writing to register will send value from shadow register to Modbus devive to address given in written value on **write** operation | 16 | | ||
| | 60031 | **Read Register**. Read from this register will send read inquiry to Modbus device (PLC controller will be in Sleep till Register value received from Modbus device). Writing to this register will send ready inquiry to Modbus device. The value written is used as Register address to read | 3 | | | 60031 | **Read Register**. Read from this register will send read inquiry to Modbus device (PLC controller will be in Sleep till Register value received from Modbus device). Writing to this register will send ready inquiry to Modbus device. The value written is used as Register address to read | 3 | | ||
| - | | 60035 | **Write multiple coils**. Write multiple coils command indicates the 16-bit address of first coil to write, the number of coils to write, number of bytes of coil values to follow, and the coil values. The response will be the address of the first coil and the number of coils. | 15 | | + | | 60035 | **Write multiple coils**. Low 16 bits of the value indicates the address of the first coil should be written. The high byte of the value (value>>24) indicates number of coils to write. The value latched in 60019 register will be sent to the device. | 15 | |
| | 60037 | **Write single register**. Write single register indicates address of the holding register and the new value of the register. The response, similarly, is the address of the register and the new value. | 6 | | | 60037 | **Write single register**. Write single register indicates address of the holding register and the new value of the register. The response, similarly, is the address of the register and the new value. | 6 | | ||
| | 60038 | **Write single coil**. Requests the 16-bit address of the coil, and the value to write (0 for OFF, FF00 for ON) | 5| | | 60038 | **Write single coil**. Requests the 16-bit address of the coil, and the value to write (0 for OFF, FF00 for ON) | 5| | ||
plc/plc_modbus_api.1571751835.txt.gz ยท Last modified: 2019/10/22 09:43 by ivan