Watlow D4T Data Logger
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Chapter 5 Function Reference
Count
Indicates the current count.
Range: 0 to 9,999
Note:
The count is not retained through a power loss; it is set equal to the Load Value upon
power up.
Note:
The count value rolls over at the ends of its range. If the count is incremented at 9,999 it
indicates 0 and additional increments count up from there
Counter Errors
If the CNT input has an error, the count will not increment or decrement. If the RST input has
an error, the count cannot be reset. An error on one input does not impact the operation of
the other input and its associated function. Regardless of errors on the inputs, the value of
the output is set according to the count and target values and the output never has an error.
The counter function never generates or propagates an error.
Error Condition
Result
- CNT has an error
- RST has no error The count does not increment or decrement but can be reset.
- CNT has no error
- RST has an error The count increments or decrements normally but cannot be reset.
Both inputs have
errors
The count does not increment or decrement and cannot be reset.
Digital Inputs/Outputs (I/O)
Use a digital input/output block to connect a field I/O device’s signal to the application. This
FB can be configured as either a digital input that can be triggered by an external device or a
digital output that can switch an external device. As an output, the block can accept either a
digital (on/off) signal or an analog percentage signal.
The block is configured as an input or output with the Direction parameter. These options for
the Direction parameter setting are described in detail in the following sections:
: the block’s output is on when a switch closure is detected by the corre-
sponding input on the flex module.
: the block drives the corresponding output on the flex module according to the signal
connected to the block’s input.
: the block’s output is on when a sufficient voltage is detected by the corre-
sponding input on the flex module.
Input Dry Contact
Use this function to integrate a signal from a switch or contact in a field I/O device into the
application. For example, use a dry contact to detect the state of a door switch connected to
a digital I/O point on the data logger.
This FB is found on the canvas of the FB diagram. The number of these FBs that are available
depends on the number of digital I/O flex modules installed and configured as dry contact in-
puts.
