Abstract: In a distributed process-control system, program-controlled apparatus is provided for permitting an operator to control the mode of a Sequential Function Chart (SFC) to place the Chart in any of five different modes as a convenience in monitoring, editing and/or changing the SFC program. These modes are: OFF mode, for temporarily disabling operation of the SFC Chart, an AUTO mode which allows the SFC program and Chart to run as configured, a HOLD mode which freezes the chart in its current state, a MANUAL mode enabling the operator to force the Chart to an operator-selected step while the output of the current step is maintained active, and a TRACE mode enabling the operator to view the steps in the Chart sequentially, and to force the steps without executing them.