Instruction manual

Timers
112
890USE18300 September 2003
Physical Output The output from a delay-to-start timer block is a Boolean 1 or 0.
If the output is not inverted, the output goes to 1 when the block reaches its
specified terminal count and stays at 1 as long as the timer accumulator holds the
terminal count. The output falls to 0 when the block looses the terminal count.
If the output is inverted, the output goes to 0 when the block reaches its specified
terminal count and stays at 0 as long as the timer accumulator holds the terminal
count. The output is 1 when the block looses the terminal count.
The physical output (See Configuring the Physical Output from a Reflex Block,
p. 27) needs to be mapped to an action module:
The action module may be a digital output module on the island bus. In this case,
you need to specify one of the digital output channels as the destination for the
block’s output.
If the timer is the first block in a nested reflex action, the action module needs to
be the same action module as the one specified for the second reflex block.
Specify the channel as None.
When the output of a block is mapped to a channel on a digital output module, that
channel becomes dedicated to the reflex action and can no longer use data from the
fieldbus master to update its field device. The fieldbus master still has the ability to
write data to this bit address in the NIM, and the reflex action editor lets you use this
data from the fieldbus master as an input to the block.
Power-up and
Fallback
Upon power-up, the timer’s output data is reset to 0.
If an error causes the timer block to go to its fallback state, the output freezes in its
last active state. Upon removal of the error condition, the timer is reset to 0.