Using the IntelliLogger™
53
F
REQUENCY
/D
ISCRETE
O
UTPUT
C
HANNELS
(C
HANNELS
S-U)
Channels S, T and U are dedicated as Output Channels, and can
be configured to run as either Discrete (On/Off) Outputs, or as Frequency Outputs.
Figure 3-26; Location of Channels S through U
Discrete; Open Collector Outputs
In Open Collector mode, these channels perform identically to Channels I through P
(described above).
Frequency Output Mode
When configured for Frequency Output Mode, these channels accept an integer value
(provided by the Program Net) and use it to generate a square-wave output.
T
HE
F
REQUENCY
O
UTPUT
S
IGNALS
:
Two methods of interface to the Frequency Output exist:
♦
Voltage Output: The output is a driven square-wave which cycles
between a Low state (the output is shorted to circuit ground “-“) and
a High state (the output is pulled up to an internal 3.3Vdc supply
through a 1Kohm resistor). Under no-load conditions this results in a
3.3Vdc square-wave output. Under load, the 3.3Vdc signal will
droop due to voltage losses across the 1Kohm pull-up resistor.
♦
Open Collector Output: Although not truly an open collector output
(since there is a 1Kohm resistor to the internal 3.3Vdc supply) loads
can be interfaced to this output as if it is an Open Collector output.
Care must be taken to not exceed 10Vdc on any applied load
external supply else the 3.3Vdc supply will be back-fed through the
internal 1Kohm resistor.
