QTech Data Systems Wireless Point to Point (WP2P) - Digital I__O - Manual (Page 2)

Wireless Point to Point - DIGITAL – Quick Start Guide – v2.1 – June 2013 2
www.qtech.co.nz Tel: 03 3663713
Wireless Point to Point System
Wireless Point to Point (WP2P) modules can be used to link electrical devices together in
situations where the physical separation or terrain between them would make direct wiring
uneconomic or impractical.
The WP2P modules incorporate high speed digital radios which have a range of up to three
kilometres. The most basic WP2P system comprises two WP2P modules which have been
configured as a pair. The modules simply use their onboard radios to communicate their input
state to the other module.
Each WP2P - DIGITAL module has three switch inputs and three relay outputs.
Digital I/O
The WP2P modules operate by copying the state of each switch input to the corresponding
relay output on the other WP2P module. When a switch input is closed, the relay output on
the other module will close, and when the switch is released, the relay will open again.
WP2P Module 1
Close switch contact on “INP1” WP2P Module 2
“RLY1” closes operating light
The delay between an input activating and the corresponding output activating is normally
less than 0.2 seconds (see note at end). With such a fast response time, the WP2P modules
can be used for flow meter pulse applications, allowing pulse rates of up to 5 pulses per
second to be communicated.
Link Status Indicator
WP2P modules have a Link status LED which is located next to the power connector.
This is to assist with site diagnostics and checking by indicating the state of the
communications link between pairs of WP2P modules.
The Link light functions as follows:
• OFF – Module failure, no power, fuse blown, circuit failure, etc.
•
SLOW FLASH – Module functioning but no communication with its partner module.
•
ON – Healthy wireless communications. The LED will briefly flicker each time it
receives messages from the other WP2P module.
Link Status indicator is based on the “keep-alive” message the WP2P modules send if it has
been longer than 30 seconds since they last sent a message. Therefore if one of the modules
is turned off, then it will take no longer than 30 seconds for the other module to detect that the
link is down and begin flashing the Link Status LED. If the connected I/O is changing more
frequently than once every 30 seconds, then they don’t need to send keep-alive messages.