Frequently Asked Questions (FAQ)
Q: What is meant by "Line of Sight" when ranges of radio links are given, can I get any idea how far the radio system would be likely to operate over ?
A: Radio frequency signals are effected by many environmental and man-man obstructions and interference. Some objects will reflect signals and can lead to increase in signal strength at certain locations. Other objects can absorb radio frequency signals and cause a drop in signal strength at a certain location. There are times when the weather can interfere with signals at various times (for example, a bunch of trees between 2 wireless units may be fine on dry days but alter the signal when it rains). Other factors are the landscape itself, a hill can obstruct signals between wireless units. This just mentions a few of the issues that can effect radio signal transmission range. As their are so many factors involved, it is extremely difficult to quote the range expected for a particular unit unless we were to physically attend each site and perform on-site surveys. What we can do however is give an indication of how far the system would be expected to operate under ideal conditions where the antennas of both ends of the link were placed high off the ground and had no obstructions between them. This range can then be compared with the Line-of-Sight range of our other systems to help determine which is most appropriate for your application.
Generally, if the line of sight range were estimated at 10km and your site had some trees and maybe the antennas are close to some sheds, you may expect around 3-4km.
Q: If radio frequency signals are effected by interference, how reliable is the system, can I be assured that the information will get through ?
A: Apart from our Handheld transmitter units. All systems are "Bi-Directional". This means every transmissions must receive a positive acknowledgement from the other end of the link for every packet of information sent. If any packet is not acknowledged, the originating end of the wireless link will resend until the packet does reach the destination. If for some reason the packet could not be delivered. BOTH the transmitting end and the receiving end of the link will activate a local alarm to inform the user that there is a radio telemetry link failure. Many of our systems are provided with optional GSM dialers that will send an emergency text message directly to your mobile phone in event of a failure. Our systems are designed to provide rock-solid ongoing performance, generally a communications fault could occur due to a lightning strike, broken antenna, loss of power at one end of the link etc). The handheld transmitter unit does not require an acknowledgement as the operator can see the results of the wireless operation occurring. All our systems also employ 16-bit CRC (error check information sent with each packet to ensure the received data is valid) and a special header that must be present before the receiver will even begin to process the packet.
Q: You mention lightning strikes, is there something I can do to lower the risk of damage from a lightning strike.
A: Yes. Though not much can be done to prevent damage from a direct hit, much damage to systems can occur as a result of induced voltages in the antenna system or power supply by strikes nearby. Radio based systems have the advantage that they do not require long (hundreds of metres) cables to be run across paddocks between electronic equipment. This is a major risk factor for induced damaging voltages from lightning activity. If you live in an area prone to lightning strikes, we recommend use of a LIGHTNING SURGE PROTECTOR. Orbit can supply appropriate surge protectors to meet your requirements.
Q: Do you stand by your product, what if I need some technical pre or post sales support.
A: Orbit Communications offer full 3 year warranty on most of our products. We offer ongoing free technical support direct from Orbit by phone, fax and email. Exceptions are any systems that we state must be installed by authorised Orbit installation personnel.
Q: Why do you supply products on different radio frequencies, would it not be better if all your systems operated on the same frequency.
A: We have found that there are advantages and disadvantages for using various frequencies for different applications. The most obvious response would probably be that we like to fit the best solution to meet your requirements. In addition to this, we export product to various countries outside Australia and not all countries share the same frequency allocations for various types of equipment. For Example: Much of Europe and Australia use 433MHz whereas NZ has 303MHz and US has 915-928MHz. Other reasons are that lower frequencies tend to travel further and will "bend" a little around the Earth whereas 2.4GHz is a much more direct "line of sight" transmission and tends to reduce in level quickly as the signal travels through the air (less range). This means the 151MHz units are great for outdoor longer range applications and 2.4GHz units are better suited for point-to-point applications. The Table below may help show some of the properties that we consider when we offer a particular system and operating frequency for your application.
Q: Do you have any customers currently using your systems that I could contact as a reference ?
A: Yes, please contact us for details and we will be happy to provide you with reference companies