TONR — On-Delay Timer
TONR is the Structured Text on-delay timer function block in rungs.dev. It uses FBD_TIMER and mirrors the behavior of the ladder TON instruction.
TOFR — Off-Delay Timer
TOFR is the Structured Text off-delay timer function block in rungs.dev. It uses FBD_TIMER and mirrors the behavior of the ladder TOF instruction.
RTOR — Retentive Timer
RTOR is the Structured Text retentive timer function block in rungs.dev. It uses FBD_TIMER and mirrors the behavior of the ladder RTO instruction.
CTUD — Count Up / Down
CTUD is the Structured Text up/down counter function block in rungs.dev. It uses FBD_COUNTER and combines the roles of ladder CTU and CTD instructions.