Technical Support - Frequent Asked Questions
What about exposure to water? Pendant and watch style transmitters are water resistant to 60 feet of pressure. Alarm Electronics will replace at no charge any transmitter which is damaged by water in normal use. Because of the possibility of the seal being damaged with time and handling, if a transmitter is used in an environment which exposes the unit to water, frequent routine testing is a necessary requirement of use. Transmitters are not intended for constant exposure to water for extended times or exposure to high temperatures, chemicals, strong soaps, cleaning agents, solvents, etc. Users of these products should be made aware of these limitations. In addtition we recommend the PLS-style bands for the watch style transmitters which will see a water environment.
What about watch bands? The watch style transmitters are supplied with bands. They will also accept any standard 11/16" replacement band available from your local department store. The leather, flex, and waterproof bands as well as other accessories are available from Alarm Electronics Mfg. Co., Inc.
What about battery life? The pendant and watch style transmitters are powered by lithium batteries which are not replaceable. Lithium batteries lose about 1-2% of their total capacity per year of shelf life and after 10 years should have 80% of their initial capacity less any discharge due to use. In the typical application the capacity for use is 10,000 operations of one second duration. The DW-101A auxillary transmitter batteries can be changed. The life depends on whether the input circuit is N/O or N/C and how frequently the transmitter is activated. If the input sensor circuit is N/C (normally closed) or the reed switch is used, the maximum battery life is typically 3 to 5 years due to the current drain required to monitor the closed loop. When the input circuit is N/O (normally open) and the reed switch is not used the life approaches the life of a pendant (10 years +) for seldom activated applications. The initial capacity is 50,000 activations (25,000 in supervised mode).
How do I know when the battery is low? Each Transmitter sends a battery status every time it is activated to the receiver. The 811LX, 902L, 904L and 601A receivers/decoders have a low battery output which is activated if the transmitter sends a "LOW BATTERY" condition.
What about encoding? There are approximately 65,000 possible transmitter key code combinations. The transmitters are encoded at random unless otherwise requested by the customer. Matched sets, or specific key code sequences are available at no additional cost.
What will cause a decrease in range? There are 3 possible reasons why the range would not be normal.
1. Obstructions by metal or radio absorbent materials which either absorb the radio energy from the transmitter or reflect the energy to another direction preventing the signal from reaching the receiver. Reflections also cause multi-path effects where there will be areas of poor reception within a few feet of each other. Multi-path effects can be substantially eliminated by using 2 receivers a few feet apart. Location of the receiver is also important. In general the higher elevation the better. For instance, it is better to locate the receiver in an upstairs room than in a basement if it is desired to have reception outside the home. Obstructions such as aluminum siding or foil insulation/wall paper will block 90% or more of signal. In commercial installations place the receiver away from metal partitions and below suspended ceilings.
2. EMI/RFI electromagnetic interference and radio frequency interference. Electrical or radio interference will not cause false alarms but may cause a substantial decrease in range. Typical sources are alarm panels with high clock rate micro-processor controls, radio scanners, local high power radio stations, defective dimmer controls, etc. For maximum immunity to EMI/RFI use the extended range receivers 811LX, 902L, 904L, 800LX which are superheterodyne receivers with good shielding and helical resonator antenna pre-filters.
3. A defective receiver or transmitter can result in poor range. This can be eliminated most easily by trying a different transmitter and then a different receiver. If the results are consistently poor range, then the most likely problems are with items 1 and 2 or both. If you are installing the receiver inside a control panel, there are 2 things that must be considered. There will be some decrease in range if all of the antenna is not outside the metal box. Some control panels generate considerable RF interference (noise) inside the panels due to the use of microprocessors in the controls. This may limit range because the noise masks the desired signal. It may be necessary to mount the receiver outside and away from the panel.
What happens when the transmitter does not activate the receiver or decoder even at close range? Load the key code into memory. The receivers or decoders wil not recognize any transmitter unless the key code is stored in memory. All the receivers have "teach" buttons to perform this function. On the 902L it is also necessary to program the operating mode.
Is it necessary to program a transmitter(s) into a receiver in order to operate a decoder? The 601A decoders operate independent of the receiver as far as recognizing the transmitters. The receiver itself may be used as an additional channel/zone and is likewise independent of the decoder.
THE DW-101A TRANSMITTER/601A DECODER OPERATES THE CONTROL PANEL IN REVERSE - (WHEN THE OPENING CLOSES THE PANEL ALARMS) - (WHEN THE OPENING ALARMS THE PANEL RESTORES). Make sure the RED jumper on the DW-101A is set to match the input loop - Jumper Closed = N/C loop or reed switch - Jumper open = N/O loop. When using the 601A decoder, the outputs are N/O and must be connected to the "hot" side of the zone input on the panel. The panel should be programmed to see end of line resistors and the resistors installed across the zone (not in line or series). If the decoder outputs are wired in series, the panel will operate in reverse.
Can the Input to the 601A decoder be divided between 2 receivers? Yes, The 601A decoder has 2 groups of 3 zones. One receiver can control zones 1-3 and another receiver can control zones 4-6. This is helpful when more than 1 receiver is needed to cover a large area. Up to 30 transmitters can be operated with each group.