Detailed Description

The RSOperator is a set dominant flip flop operator, or RS function as referenced by IEC 61131-3 in PLC.

The RSOperator output (Q) is set to true on rising edge in the set input (S) and false on rising edge in the reset input (R). If a rising edge is at the same time on both inputs then the reset input will dominate and the output will be set to false.

Arguments

When operator is used inside a signal its default input is automatically tied to signal's InternalValue or previous operator's output. Its default output is automatically tied to next operator's input or to signal's Value. See also CDP Operator Usage In CDP Signals.

Example

Below are the example plots for RSOperator reset input (R, cyan), set input (S, orange) and output value (Q, yellow).

Actual Processing Code of the RSOperator

unsigned int RSOperator<bool>::Process()
{
  if (!m_S)
    return STATUS_ERROR;

  if ((bool)*m_R && !m_oldR)
    *m_Q = false;
  else if ((bool)*m_S && !m_oldS)
    *m_Q = true;

  m_oldS = (bool)*m_S;
  m_oldR = (bool)*m_R;
  return STATUS_OK;
}