Using the timer block, 5 using the timer block – Micromod MOD: 1800P - MOD 30ML Identity Module (Version 2) Algorithms, Tables and Sequential Logic Functions User Manual
Page 69

Logic Functions - Book 2
TIMER BLOCK
8-61
8.7.5
Using the Timer Block
The following examples show some typical uses of a timer block.
EXAMPLE 1 Self Resetting Timer (Figure 8-32)
Timer starts timing, time out, reset, starts timing, reset, etc. This cyclic operation provides
regular pulses for use by other function blocks and to field devices via a digital output module
block. The period of the waveform created by this example is the reset input/limit difference
value plus one task scan cycle. The extra task scan cycle is the reset cycle time.
RESINP
HLSTAT
TM1
Reset Input
High Limit Status
Discrete Output to
Another Function Block
Requires No
Initiating Logic
Figure 8-32. Softwiring Drawing for Timer Block, Example 1
EXAMPLE 2 Timer Held Inoperative by Maintained Reset Source (Figure 8-33)
Timer will not start timing until reset source makes a true to false transition. Timer will then
time from reset input value to its limit.
Initiating
Logic
RESINP
Discrete Output
HLSTAT
TM2
Reset
High Limit Status
Discrete Output to
Another Function Block
R
EX1
Equation
Result
Disable Input
DISINP
Figure 8-33. Softwiring Drawing for Timer Block, Example 2