Weidmuller WI-I/O-9-U2: Wireless Mesh I/O & Gateway User Manual V1.2.2 - Manual (Page 31)

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2.5.3 Digital / Pulsed Inputs
Each digital I/O channel on the WI-I/O 9-U2 can act as either an input or an output. The
input/output direction is automatically determined by the connections and configuration
of the I/O.
If you have an I/O channel wired as an input but operate the channel as an output. No
electrical damage will occur however, the I/O system will not operate correctly.
If operating t
he channel as an output and performing a “read inputs” on this location it
will indicate the status of the output.
Marked D1-8 the Digital inputs share the same terminals as the Digital outputs on the
WI-I/O 9-U2 module.
A digital input is activated by connecting the input terminal to EARTH or Common,
either by voltage-free contact, TTL Level, or transistor switch.
Each digital input has an orange indication LED that will turn on when the input has
been connected to a GND or common.
Figure 13 – Digital / Pulsed Input Wiring
Digital inputs 1 to 4 can be used as pulsed inputs.
The maximum pulse frequency is 50 KHz for Input 1 & 2 and 1 KHz for Input 3 & 4.
Digital/Pulsed inputs are suitable for TTL signal Level, NPN-transistor switch devices or
voltage-free contacts (relay/switch with debounce capacitor).
Frequencies greater than 1 KHz need to use a TTL logic drive or an external pull-up
resistor (1K
Ω to V+). Pulsed inputs are converted to two different values internally. First
is the Pulse Count, which is an indication of how many times the input has changed
state over a configured time period. Secondly there is a Pulse Rate which is an analog
input derived from the pulse frequency. E.g. 0 Hz = 4mA and 1 KHz = 20mA.
All Pulsed Input counts are stored in non-volatile Ram so in the event of a power fail or
the module being reset the values will be saved.
WI-IO 9-U2