Modbus Function Codes for Discrete Coils/Inputs
Modbus Function Codes for Discrete Coils/Inputs
Functions
int8_t Modbus::process_FC1 (uint16_t *regs, uint8_t u8size)
This method processes functions 1 & 2 This method reads a bit array and transfers it to the master.
int8_t Modbus::process_FC15 (uint16_t *regs, uint8_t u8size)
This method processes function 15 This method writes a bit array assigned by the master.
int8_t Modbus::process_FC5 (uint16_t *regs, uint8_t u8size)
This method processes function 5 This method writes a value assigned by the master to a single bit.
Function Documentation
process_FC1()
process_FC1Modbus Function Codes for Discrete Coils/Inputs
Modbus Function Codes for Discrete Coils/Inputsprocess_FC1
int8_t Modbus::process_FC1 (uint16_t * regs, uint8_t u8size)[private]
This method processes functions 1 & 2 This method reads a bit array and transfers it to the master.
Returns
u8BufferSize Response to master length
Definition at line 1302 of file ModbusRtu.h.
01303 {
01304 uint8_t u8currentRegister, u8currentBit, u8bytesno, u8bitsno;
01305 uint8_t u8CopyBufferSize;
01306 uint16_t u16currentCoil, u16coil;
01307
01308 // get the first and last coil from the message
01309 uint16_t u16StartCoil = word(au8Buffer[ADD_HI], au8Buffer[ADD_LO]);
01310 uint16_t u16Coilno = word(au8Buffer[NB_HI], au8Buffer[NB_LO]);
01311
01312 // put the number of bytes in the outcoming message
01313 u8bytesno = (uint8_t)(u16Coilno / 8);
01314 if (u16Coilno % 8 != 0)
01315 u8bytesno++;
01316 au8Buffer[ADD_HI] = u8bytesno;
01317 u8BufferSize = ADD_LO;
01318
01319 // read each coil from the register map and put its value inside the outcoming message
01320 u8bitsno = 0;
01321
01322 for (u16currentCoil = 0; u16currentCoil < u16Coilno; u16currentCoil++)
01323 {
01324 u16coil = u16StartCoil + u16currentCoil;
01325 u8currentRegister = (uint8_t)(u16coil / 16);
01326 u8currentBit = (uint8_t)(u16coil % 16);
01327
01328 bitWrite(
01329 au8Buffer[u8BufferSize],
01330 u8bitsno,
01331 bitRead(regs[u8currentRegister], u8currentBit));
01332 u8bitsno++;
01333
01334 if (u8bitsno > 7)
01335 {
01336 u8bitsno = 0;
01337 u8BufferSize++;
01338 }
01339 }
01340
01341 // send outcoming message
01342 if (u16Coilno % 8 != 0)
01343 u8BufferSize++;
01344 u8CopyBufferSize = u8BufferSize + 2;
01345 sendTxBuffer();
01346 return u8CopyBufferSize;
01347 }
process_FC15()
process_FC15Modbus Function Codes for Discrete Coils/Inputs
Modbus Function Codes for Discrete Coils/Inputsprocess_FC15
int8_t Modbus::process_FC15 (uint16_t * regs, uint8_t u8size)[private]
This method processes function 15 This method writes a bit array assigned by the master.
Returns
u8BufferSize Response to master length
Definition at line 1447 of file ModbusRtu.h.
01448 {
01449 uint8_t u8currentRegister, u8currentBit, u8frameByte, u8bitsno;
01450 uint8_t u8CopyBufferSize;
01451 uint16_t u16currentCoil, u16coil;
01452 boolean bTemp;
01453
01454 // get the first and last coil from the message
01455 uint16_t u16StartCoil = word(au8Buffer[ADD_HI], au8Buffer[ADD_LO]);
01456 uint16_t u16Coilno = word(au8Buffer[NB_HI], au8Buffer[NB_LO]);
01457
01458 // read each coil from the register map and put its value inside the outcoming message
01459 u8bitsno = 0;
01460 u8frameByte = 7;
01461 for (u16currentCoil = 0; u16currentCoil < u16Coilno; u16currentCoil++)
01462 {
01463
01464 u16coil = u16StartCoil + u16currentCoil;
01465 u8currentRegister = (uint8_t)(u16coil / 16);
01466 u8currentBit = (uint8_t)(u16coil % 16);
01467
01468 bTemp = bitRead(
01469 au8Buffer[u8frameByte],
01470 u8bitsno);
01471
01472 bitWrite(
01473 regs[u8currentRegister],
01474 u8currentBit,
01475 bTemp);
01476
01477 u8bitsno++;
01478
01479 if (u8bitsno > 7)
01480 {
01481 u8bitsno = 0;
01482 u8frameByte++;
01483 }
01484 }
01485
01486 // send outcoming message
01487 // it's just a copy of the incomping frame until 6th byte
01488 u8BufferSize = 6;
01489 u8CopyBufferSize = u8BufferSize + 2;
01490 sendTxBuffer();
01491 return u8CopyBufferSize;
01492 }
process_FC5()
process_FC5Modbus Function Codes for Discrete Coils/Inputs
Modbus Function Codes for Discrete Coils/Inputsprocess_FC5
int8_t Modbus::process_FC5 (uint16_t * regs, uint8_t u8size)[private]
This method processes function 5 This method writes a value assigned by the master to a single bit.
Returns
u8BufferSize Response to master length
Definition at line 1389 of file ModbusRtu.h.
01390 {
01391 uint8_t u8currentRegister, u8currentBit;
01392 uint8_t u8CopyBufferSize;
01393 uint16_t u16coil = word(au8Buffer[ADD_HI], au8Buffer[ADD_LO]);
01394
01395 // point to the register and its bit
01396 u8currentRegister = (uint8_t)(u16coil / 16);
01397 u8currentBit = (uint8_t)(u16coil % 16);
01398
01399 // write to coil
01400 bitWrite(
01401 regs[u8currentRegister],
01402 u8currentBit,
01403 au8Buffer[NB_HI] == 0xff);
01404
01405 // send answer to master
01406 u8BufferSize = 6;
01407 u8CopyBufferSize = u8BufferSize + 2;
01408 sendTxBuffer();
01409
01410 return u8CopyBufferSize;
01411 }