GE PACSystems RX7i - Page 244

Chapter 4. Ladder Diagram (LD) Programming
GFK-2950C February 2018 229
Operands
TOF, TON and TP have the same input and output parameters, except for the instance variable,
which must be the same type as the instruction.
Note: Writing or forcing values to the instance data elements IN, PT, Q, ET, ENO or TI may cause
erratic operation of the timer function block.
Parameter
Description
Allowed Types
Allowed Operands
Optional
????
Structure variable containing the internal
data for the timer instance. (Refer to Data
Required for Standard Timer Function Blocks.)
TOF, TON, or TP.
Must be same type
as the instruction.
NA
No
IN
Timer input. Controls when the timer will
accumulate time.
TON and TP will begin to time when IN
transitions from OFF to ON.
TOF will begin to time when IN transitions
from ON to OFF.
Flow
NA
Yes
PT
Preset time (in ms). Indicates the amount of
time the timer will time until turning Q either
ON or OFF, depending on the timer type.
Setting PT to 0 resets the timer.
DINT
All except S, SA, SB,
SC
Yes
Q
Timer output. Action depends on the timer
type.
When TP is timing, Q is ON.
When TON is done timing, Q turns ON.
When TOF is done timing, Q turns OFF.
Flow
NA
Yes
ET
Elapsed time. Indicates the length of time, (in
ms), that the timer has been measuring time.
DINT
All except S, SA, SB,
SC and constants
Yes