User manual

Manual WWP-IIRO-8
6
The units are packaged in NEMA4 enclosures for remote installation in harsh environments.
These units act wirelessly, saving time and money associated with wired installations. The units
can work at various distances up to 7 miles with the standard antenna shipped with the product.
Alternate antennas may be used to boost signal strength.
The 8 isolated inputs can be driven by either AC or DC signals and are not polarity sensitive.
Input signals are rectified by photocoupler diodes. Standard 12/24 AC control transformer outputs
can be accepted as well as DC voltages. The input voltage range is 3 to 28 volts (rms). Unused
power dissipates through a 1.8KΩ resistor. External resistors connected in series with this may
be used to extend the input voltage range. Each input circuit contains a switchable slow/fast filter
that has a 4.7 ms time constant. (Without filtering, the response is 10 μs) The filter must
be
selected for AC inputs in order to eliminate response to zero crossings, however, it is also
valuable for use with slow DC signals in a noisy environment. A filter is individually selected when
a jumper is installed onto any of the positions ‘FILTER 0' thru ‘FILTER 7'.
A built-in watchdog timer resets the unit if the microcontroller "hangs up".
Figure 1-1: Block Diagram Depicting One-Way Signal Flow