![[spacer image]](/images/spacer_white.gif){kind=small}
Hardware
Q: How many wireless sensors can be supported by the Wireless Gateway?
A: One Wireless Gateway can support up to 100 sensors. To expand the network beyond 100 sensors, simply add another Wireless Gateway to the network and continue expanding.
Q: What frequencies do the wireless sensors communicate on?
A: OEMSensors.com's wireless sensor network currently operates in the ISM 900MHz (902-928MHz) band of frequencies. We support 250kbps data rate transfers in this frequency. (Coming soon in 2010: 433Mhz, and 868MHz)
Q: What should I do with my wireless sensor when the battery dies?
A: The average life span of a wireless sensor varies depending on how often the sensor is set-up to transmit to the Wireless Gateway. That said, on average you should expect over 1 year of battery life from a sensor with a heartbeat of 1 hour. (Longer heartbeats increase battery life.) Once the battery has been depleted, you can change the battery by peeling the stickers away from the battery slot and battery removal hole then using the battery removal tool push the battery out and replace with a new CR2032 coin cell battery. We encourage you to recycle the old battery.
Q: Do you have a cellular gateway for your wireless sensor network?
A: OEMSensors.com currently offers a USB wireless gateway for our wireless sensor networks. Cellular and Ethernet gateways are in the works and will be available Spring 2011.
Q: Can I add additional sensors to the wireless sensor network at a later time?
A: Yes. You may expand your network as needed, up to 100 sensors per USB gateway. Upon reaching 100 sensors, we recommend you purchase an additional wireless gateway. This will lead to the best performance of your wireless sensor network.
Q: What do I need to have in my possession to run an OEMSensors.com wireless sensor network (WSN)?
A: To deploy an OEMSensors.com wireless sensor network, you will need an OEM Ethernet or Cellular Gateway, or a PC that is always powered on with an internet connection using an OEM USB Gateway.
Q: Should I expect interference from other wireless networks (WiFi, walkie talkies, cordless phones, cellular phones, radios, etc.) operating in the vicinity of my wireless sensor network (WSN)?
A: No. OEM Sensor's wireless sensors currently operate in the 900Mhz ISM band. Most wireless sensors today operate in the crowded, 2.4Ghz space where cell phone, WiFi networks, wireless telephones, and many wireless accessories for networks and PCs operate.
We chose the 900Mhz frequency for its performance characteristics (much better range through obstacles than 2.4Ghz) and "openness" of the frequency. Operating at 900Mhz limits the ability to deploy sensors to a specific region (North America only).
The chipset used by our wireless sensors also supports 868MHz as well as 433MHz. Support for international markets will utilize these two frequencies for best performance.
Q: What are the voltage input requirements for the OEM/RF wireless sensor circuit boards?
A: We support V in 2 - 3.6 VDC max.
Q: What is the power draw of a wireless sensor?
A: In sleep mode the sensor consumes .5µ Amps and during transmit the sensor consumes 35 mA.
Q: What is the average life span of the battery in the wireless sensors?
A: The life span of the battery is dependent on a number of factors: how long the sensor is "sleeping" (a sensor will draw nominal power during sleep state ~.5µ Amps); how long it takes the sensor to reach its awake state, and how long it is on, using the radio to transmit the data to the Wireless Gateway.
We estimate through normal usage, that a sensor in the field should last over 1 year at a 1 hour heartbeat before it needs to be replaced.
Q: What happens to my wireless sensor network if the PC being used as the application host goes into sleep mode or is powered off for some reason?
A: If the Wireless Gateway is unable to receive transmissions from the sensors due to the PC being off, or the gateway not being installed, the sensors will continue to try and link with the gateway (two times by default). If it is unable to link to the gateway it will enter “link mode” where it will search for a nearby gateway. If no gateway is found, the sensor enters "power save" mode, and will sleep for two hours before entering link mode again, and scanning all available channels for a gateway. This process will continue until the sensors find a gateway to communicate with.
Note: While the gateway is off, no data is being collected and no notifications can be transmitted.
Q: Does the USB Wireless Gateway need to be plugged directly into the computer, or can I plug it into a USB port expander?
A: If you are using an unpowered USB port expander/hub, the USB Gateway will not operate properly. To insure best performance of the Sensor Network, plug the USB gateway into a powered port expander, or best yet is to plug the USB gateway directly into a USB port on your computer.
Q: How many hops can your wireless sensor network manage?
A: Our wireless sensor networks are configured to allow one hop. That is: Wireless Sensor <-> Wireless Repeater <-> Wireless Gateway.
You can use more than one repeater on a single sensor network, however the repeaters will not not hop between each other at this time. Each repeater can communicate to any wireless sensors within range, and the wireless gateway (not other repeaters).
Q: What are the size of the data packets being transmitted by the sensors to the gateway?
A: The application data is 18 bytes in length and the total TX packet size is 40 bytes.
Q: How do I mount the wireless sensors for my particular application?
A: We have provided a number of mounting options for the sensor technology. In the deployment kits we have included screws and double-sided tape. These options should allow you to mount the hardware to most any type of material.
Q: My temperature sensor is giving me a reading of -1767.8F (-999.9C), what does this mean?
A: A reading of -1767.8F signifies that the thermistor wires have broken or the battery has not been fully inserted causing a short between the thermistor leads on the sensor board. If this happens; try removing the battery, wait 45 seconds then re-insert the battery making sure to push the battery all the way to the back of the sensor housing. When the sensor comes back online check the reading to see if it has been corrected. If the problem persists you will need to contact OEMSensors.com customer support at 877-561-4555 for more information.
Q: How do my wireless sensors connect to the monitoring software on the internet?
A: Each wireless sensor comes ready to connect to the Wireless Gateway upon power up. Make sure that the USB Driver has been installed and the Gateway Software is installed and running, then simply insert the USB gateway into the PC. Once the gateway establishes a connection with the wireless sensor monitoring software and registers itself, simply insert the batteries into their holder on each sensor. The sensor will power up and connect to the Wireless Gateway and register with the software, assigning each sensor its own unique id number.
Q: How sensitive is the wireless temperature sensor?
A: The thermal range of our wireless temperature sensor is -50°C to 150°C (-58°F to 302°F). It's accuracy is +/- 2°C (+/-3.6°F) with single point calibration. This sensor is suitable for most commercial and consumer applications.
Q: Will a wireless sensor notify me when I need to change the battery?
A: Each time the sensor transmits data to the Wireless Gateway, the sensor reports the batteries life as a percentage of the life left. It is not an exact reading, but will provide you with enough information to know when the battery is about to expire.
Software
Q: How do I get my sensors to stop sending alerts to my email or phone when they are inactive?
A: Logged in as the administrator, you can halt the alerts by doing the following:
1. Select the sensor you wish to edit (it could be named "Temperature 1" or you may have renamed it to
something else).
2. Click on the edit box next to the sensor name (looks like a pencil).
3. You will see the "Basic Sensor Configuration. Below it is an underlined "Advanced Configuration" link. Select it.
4. You are now in the Advanced Sensor Configuration Screen. Select the field titled "Inactivity Alert (Minutes)."
5. Insert a "0" (zero) into the field.
6. Click "Save."
7. Your sensor will now stop sending you notifications that the sensor is inactive.
You can also do a mass configuration of the network of this feature by doing the following:
1. At the bottom of your sensor list is a link titled "Configure Multiple Sensors."
2. Click on the link.
3. Check all of the sensors you wish to include in the configuration.
4. In the "Inactivity Alert (Minutes)" field, insert a "0" (zero) into the field.
5. Click "Save."
If you have additional questions regarding this feature, please email us at support@oemsensors.com.
Q: What happens to the data from my wireless sensor network if the power to my Wireless Gateway is off or disrupted?
A: While the gateway is off, no data is being collected and no notifications can be transmitted by the sensor. In short, the data is being discarded by the sensor.
If the Wireless Gateway is unable to receive transmissions from the sensors due to the PC being off, or the gateway not being installed, the sensors will continue to try and link with the gateway (two times by default). If it is unable to link to gateway it will disassociate itself from the gateway and enter “link mode” where it will try to find a gateway nearby.
Q: How do I make changes to the wireless sensor parameters?
A: Configuration data is entered into pages from the web application used by the administrator and stored in the database on the server. At regular intervals the Wireless Gateway requests configuration data from the server and stores this data locally. Independent of this sequence, sensors wake up and start communicating with the gateway. If there is data for the sensor stored in the Wireless Gateway then the data is transferred to the sensor. After the data, if any, is transferred, the sensor goes back into sleep mode.
Q: What happens if I push "Reset Network" in the Gateway Application?
A: Pressing the "Reset Network" button in the Gateway application will release the USB Gateway's wireless channel and re-scan for the clearest available wireless channel. On each sensor's next heartbeat, it will enter link mode and rescan to find the Gateway. It is recommended to reset your network if any of your sensors are have problems checking in regulary.
Q: How secure are the communications on the wireless network?
A: We use the same encryption methods used by websites to transmit financial data. Secure socket layer (SSL) protocol is employed with 256-bit data encryption making data hosted on your network secure.
Q: What software do I need to install to initiate the wireless sensor network?
A: In order to use a Wireless Sensor network you will need to download and install the USB drivers for the Wireless Gateway and the Gateway Software which will allow your sensors to communicate with the online system. No additional software or drivers are required.
Q: Is it possible to control a remote device using your wireless sensors?
A: You can use OEM Wireless Sensors to control simple on/off switches. The interface is CMOS with output drive capability so driving a simple “Hi/Low” can be used on demand. Anything beyond that can not be controlled.
General Questions
Q: How does the wireless sensor network notify the user there is an incident that requires an action?
A: The wireless sensor monitoring software notifies the designated contacts(s) via SMS (text message) or e-mail.
During the set-up process of a user account, the administrator can program in cell phone numbers and e-mails of the individuals requiring notification, establishing the contact criteria for each of the above three methods of communication.
Q: How much will I be charged for text message notifications?
A: You will not be charged by OEMSensors.com for text messages issued by the Sensor Network. The text messages you receive from us are routed through your cellular provider. Thus, any text message notifications you set-up to receive from the software are covered under your text message plan through ATT™, Sprint™, Verizon™, T-Mobile™, et al. If you do not subscribe to a text plan through your cellular carrier, you will be charged their standard rate for receiving a text message.
Q: Will I need to buy or replace the batteries for my wireless sensors?
A: Batteries are included with the purchase of every wireless sensor that ships from our store. Under normal operating conditions a sensor in your wireless sensor network (WSN) will last for 3,000 transmissions (2-4 years with a 1+ hour heartbeat.)
Q: Are there environmental attributes that will not allow the wireless sensors to function?
A: Wireless sensors transmit their data using wireless radios, and as such are subject to the same environmental limitations found in all wireless communications. Elements that effect radio transmission are severe inclement weather, trees, heavily constructed walls (cement, cinder block), sheet metal, wall board, wood, tile, buildings, vehicles, etc. Unless you have direct line of sight, every obstruction impedes wireless transmissions, even the human body.
In short, there are four factors to keep in mind for the health of your wireless sensor network and maintaining its peak performance:
• distance from sensor-to-sensor and the wireless gateway
• power output of the radio
• data rate transmission
• frequency of the radio link
Q: How do I pay for my products?
A: We provide a variety of ways that you can pay for your products. Orders can be placed via credit card, money order, or check by contacting an OEMSensors.com sales representative for personal assistance.
Q: What is your return policy?
A: In order to return your product for an exchange or refund, you must first contact your OEMSensors.com sales representative and request a return merchandise authorization (RMA) number. You can reach your sales representative at 801-561-5555.
No packages will be accepted without the RMA number clearly marked on the outside of the package. After inspecting and testing, we will return your product, or its replacement using the same shipping method used to ship the product to us within 30 days. In your package, please include a daytime telephone number and a brief explanation of the problem.
