QTech Data Systems Wireless Point to Point (WP2P) - Digital & Analogue I__O - Manual (Page 4)

Wireless Point to Point - DIGITAL & ANALOGUE - Quick Start Guide – v1.1 – June 2013 4
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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.
WP2P Repeater Module
A WP2P Repeater Module is available to increase the range and coverage of a WP2P
system. It is used in situations where the WP2P modules are a long way apart or there is an
obstacle preventing line-of-sight between them.
The WP2P Repeater Module operates by listening for complete and valid WP2P messages
and then re-transmitting them. It can be used with both WP2P DIGITAL and WP2P DIGITAL
& ANALOGUE type modules simultaneously.
Please refer to the Repeater Quick Start Guide for further details.
Power Supply Notes
Power Supply & Current Consumption
The WP2P operates from a nominal 12 Volt DC power supply.
Current consumption is ~66mA in standby (no output relays active) to 83/100mA (one or two
relays active).
The power connector is a 2.1mm DC Socket, centre pin positive. The supply voltage should
be clean, continuous and transient free with an output of 12 Volts +/- 1.5 Volt DC. The WP2P
incorporates reverse and overvoltage protection.
The absolute maximum supply voltage is 13.8 V DC and any solar/battery design needs to
take this into account.
Warning – Do NOT use Switch Mode Power Supplies (SMPS) with this product. The
DC power supply used for this product MUST have a grounded negative or be a
“linear” transformer based plug pack. The reason is that the aerial, programming port
and external connections can provide exposed earth points and the SMPS can impose
an AC voltage on the DC ground, which can lead to damage. Suitable cost effective
plug packs are available from QTech P/N PD5412, PD5413 & PD5414.
Internal Fuse
The WP2P module circuit is protected by a 20mm x 5mm 500mA fast blow fuse. This is
located on the internal circuit board. To access the fuse, remove the top cover by prizing it off
its retaining dimples. Only replace the fuse with an identical type, do not use alternatives.
This fuse will blow if the power supply maximum voltage is exceeded.