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en-us_commands:reference:imcmem

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IMcMem()

IMcMem() sets the sizes of X, Y, M and D memory used by MC Protocol.

IMcMem command operation flow

void IMcMem(uint16_t x_size, uint16_t y_size, uint16_t m_size, uint16_t d_size)

Commands

Command Arguments Return Value Operation
IMcMem(x_size, y_size, m_size, d_size) uint16_t x_size — Number of X input bits
uint16_t y_size — Number of Y output bits
uint16_t m_size — Number of M internal bits
uint16_t d_size — Number of D words
void Sets the sizes of X, Y, M and D memory used by MC Protocol.

Example

void setup() {
  IMcMem(32, 32, 64, 64);  // Set the X·Y·M·D memory sizes used by MC Protocol.
  IMcAdr(0, 0, 0, 0);  // Set the start addresses of X·Y·M·D memory.
  IMcInit(Serial2, 1, 9600);  // Set the communication port, station number and baud rate.
}
 
void loop() {
  IMcProtocol();  // Check incoming requests and process MC Protocol responses.
  if (X != nullptr) X[0] = IdigitalRead(0, 5);  // Read the input repeatedly and update only if all samples match. If HIGH and LOW are mixed, retain the previous stable state.
  if (Y != nullptr) digitalWrite(32, Y[0] ? HIGH : LOW);
}

Precautions

  • Keep calling IMcProtocol() in loop().
  • Do not confuse hexadecimal addressing for X/Y with decimal addressing for M/D.
  • Do not use X/Y/M/D before allocating the pointers.
  • If Cnet or Modbus reallocates shared M/D memory at runtime, the addresses used by MC Protocol change. Complete all memory size settings in setup() and do not call them again at runtime.
  • Allocation functions do not return success status. For nonzero sizes, verify the corresponding global pointer is not nullptr before accessing it.

Built-in Commands in the Same Category

en-us_commands/reference/imcmem.1788796399.txt.gz · Last modified: by 127.0.0.1

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