mycnc:host_modbus_api
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Host Modbus API
Modbus Master API is implemented in myCNC software.
Host computer with myCNC able to read Input registers and write data Holding registers from/to modbus Slave device.
User API is available through the Software PLC.
Register Name | Address | Description |
---|---|---|
GVAR_XMODBUS_SERVER_ADDR | 5750 | Writing to this register sets Modbus Server Address |
GVAR_XMODBUS_VALUE | 5751 | Writing to this register sets a Value that will be sent while write to Modbus Server |
GVAR_XMODBUS_ADDR2READ | 5752 | Writing to this Register sets Address of Global register to put a result of Modbus Read operation |
GVAR_XMODBUS_READY_READ | 5753 | Ready Read flag. The value is automatically cleared ion start of Modbus read operation. If Read is finished successfully, the value is set to “1”. If Read operation is failed, the value is set to “-1”. |
GVAR_XMODBUS_WRITE | 5755 | Writing to this register initiates Modbus Write operation. Written value is Modbus Server Register address (for Write). A value defined in register 5751 will be sent |
GVAR_XMODBUS_READ | 5756 | Writing to this register initiates Modbus Read operation. Written value is a Modbus Server Register address (for Read). Writing to this register will clear READY_READ register (5753). The READ_READY register value will be set to “1” when Read completed successfully. The READ_READY register will be set to “-1” if Read Error happens |
Example:
- Need to write a value of “999” to Modbus Server with Address #7 to register #25,
- then read register #24 and save it in global variable register #500
//Write gvarset(5750,7); //Set Modbus Server Address gvarset(5751,99); //Set a value to write gvarset(5755,25); //Write to Modbus regsiter #25 //Read gvarset(5752,500); //Set Register #500 to receive Modbus Read result gvarset(5756,24); //Read Modbus register #24 do { //wait ready_ready timer++; }while(gvarget(5753)==0); if (gvarget(5753)<0) { exit(99); //Modbus Ready Error }; a=gvarget(500); //Read modbus result can be used by reading redister #500
mycnc/host_modbus_api.1539556679.txt.gz · Last modified: 2018/10/14 18:37 by skirillov