|Version 12 (modified by 6 years ago) ( diff ),
- Is the GW SBC FCC/CE/UL, REACH/RoHS/Conflict Materials Certified?
- What is Gateworks Export Classification?
- What is the PCB Flammability Rating?
- Do your boards come with wireless/bluetooth?
- What input voltage does your SBC accept?
- Is there a battery charging circuit on your board?
- How much power / current can I get / run over a specific connector / …
- Can I clock down the processor for lower power?
- What does the reset cause indicate?
- What throughput does the PCIe lane support?
- Why are certain areas on the board warm with regards to temperature? …
- How is MTBF calculated for Gateworks SBCs?
- Do the Gateworks boards support RTOS / Real Time OS
- How to Improve Boot Speed / Times
- How to connect a LED to Ventana GPIO
- How Many Wireless Clients can Connect to my Access Point?
- I see an imx-sdma message and is it an error?
- Why doesn't the reboot or shutdown command work on my system?
This page contains answers to commonly-asked questions about Gateworks Product. If there is anything here that is not clear/available, please contact support@…
Is the GW SBC FCC/CE/UL, REACH/RoHS/Conflict Materials Certified?
Simple answer is that it depends. Because our product is used in various applications, it entirely depends on the application at hand since FCC & CE testing must be done on the complete system which includes enclosure, cables, radios, antenna, power supply, etc. Because of this, we do not have FCC/CE certifications because that is useless to our customers. However, we will work with you on getting your completed system FCC/CE certified. We have a long history of customers that have taken our SBC's and went through the various processes to get certifications on their end product.
In order to help you initially with this processes, we sell pre-certified power supplies, but if there is one that you’re interested in, we can provide the datasheet which will list it's certifications.
We also recommend you use pre-certified wifi radios. By using a pre-certified radio you can avoid having to re-certify the radio which can be more expensive since it is classified as a transmitting device. Note you must use the radio in the same configuration and with same antenna (gain) as it was certified. Check with your certification house for exact rules and regulations.
All of our products have been designed to reduce both conducted and radiated emissions and most customers make it through the approval process with minimal effort, assuming they have an adequate enclosure solution. We can also work directly with your certification house to provide the necessary documents for the certification process.
Typical costs for FCC/CE certification run from $5K to $10K assuming a pre-certified radio is used.
Gateworks recently went through an EMI chamber test on some products in the Ventana family and found very impressive results. Sitting idle, the boards passed without an enclosure or any other EMI reducing solution.
Please read more about our testing results and other FCC information here.
Tips for passing emissions include, but not limited to:
- Using metal enclosures
- All cabling must be shielded
- Proper grounding to the board
To view the emitting clocks on a Ventana board, use the command:
Gateworks uses 100% RoHS solder and builds to IPC-A-610 Class 2 standards. For more information on our manufacturing practices, please see our main site here.
What is Gateworks Export Classification?
International Terms and Definitions Export Administration Regulations (EAR)
Export Control Classification Number (ECCN) is a specific alpha-numeric code that identifies the level of export control for articles, technology and software (collectively, "Items") that are exported from member states of the Wassenaar arrangement: http://en.wikipedia.org/wiki/Wassenaar_Arrangement including the United States. The ECCN classification that applies to any specific item is determined by referring to a table that is issued for the United States by the Bureau of Industry and Security: http://en.wikipedia.org/wiki/Bureau_of_Industry_and_Security. See the Export Administration Regulations(EAR): http://www.gpo.gov/bis/index.html, codified at 15 C.F.R. http://en.wikipedia.org/wiki/Code_of_Federal_Regulations. The ECCN table contains hundreds of ECCN codes that are organized according to the technical parameters and/or end use of the hardware, software or technology that is being exported.
For Gateworks we are classified as ECCN 5A992. We can ship to any country in the world except Cuba, Iran, North Korea, Sudan, and Syria. Be sure that the SED document indicates “NLR” which means “No License Required”.
Harmonized Codes (HTS):
All of the imports and export codes used by the United States are based on the Harmonized Tariff System (HTS). The HTS assigns 6-digit codes for general categories. Countries which use the HTS are allowed to define commodities at a more detailed level than 6-digits, but all definitions must be within that 6-digit framework. The U.S. defines products using 10-digit HTS (Harmonized Tariff Code) codes. Exports codes (which the U.S. calls Schedule B) are administered by the U.S. Census Bureau. Import codes are administered by the U.S. International Trade Commission (USITC).
All Gateworks goods should be classified as: 10 digit (US Schedule B) ~ 8517.70.0000 = Parts, 6 digit ~ 8517.70 = Parts. http://www.census.gov/foreign-trade/schedules/b/
What is the PCB Flammability Rating?
The PCB is rated at UL 94V-0
Do your boards come with wireless/bluetooth?
WiFi / Bluetooth is not included on the board. We have Mini-PCI or Mini-PCIe slots that accept WiFi/Bluetooth radios. Please see our robust page on wireless communications here.
What wireless radios do you support?
Typically radios with Atheros chipsets. Read more about the radios on our Wireless Wiki Page.
What input voltage does your SBC accept?
Typically, we accept 8-60VDC input, but you should look in your User Manual for actual voltages accepted by your Gateworks product as they can vary greatly, even within the same family of product.
Is there a battery charging circuit on your board?
No, this should be handled off the board.
How much power / current can I get / run over a specific connector / Mini-PCIe slot?
Gateworks builds very robust power supplies for its 3.3V rail. This rail is primarily used by the wireless radios on the Mini-PCI and Mini-PCIe slots.
Most Ventana User Manuals indicate the wattage available to the Mini-PCIe sockets. For example, under the standard features you will typically see:
- 30W shared between all Mini-PCIe Sockets
- 15W maximum per Mini-PCIe slot.
Another example, the power supply on the Laguna GW2380 is rated to 10W total (@ 3.3V) which means 3A is available from the supply. The supply must provide power to the board (around 2.5W) and also any Mini-PCIe radios you have plugged into the board. Most standard radios run around 3.5W max which would leave around 4W for other devices. If you are using a higher wattage radio this would reduce the amount of power available to the J8 connector so this must also be considered. The J8 connector is rated for 1A per pin so you at most you would be limited to 3.3W for any peripheral powered by this connector.
The pins on the J4 are rated to 3A so they will be able to source whatever is left available up to 3A.
On a Ventana series board with a 2x5 expansion connector, the pins are rated to 1 amp. Therefore, at 3.3V this would be 3.3W of support. Note that GPIO lines are limited in current, please consult the user manual.
To find current ratings of the pins, consult the connectors datasheet.
5V rails will depend on the 5V IC behind it.
Can I clock down the processor for lower power?
Absolutely. However, in order to realize the full effect of getting 'lower power' from shifting the frequency of the CPU down, you will also need dynamic voltage scaling. Currently, this only supported on the Ventana family, of which more information can be found on our DVFS page.
What does the reset cause indicate?
When the Gateworks board boots up, information regarding the Reset cause comes out on the serial console.
Depending on how the board was 'reset', different messages will appear:
- POR - Power on Reset, this simply means the primary power supply was the cause of the reset. You can see this type of message if you unplug the power supply and plug it back in. However, this could also be caused by our GSC as it has the ability to toggle the primary power supply. Please see more information about that feature on our GSC page.
- WDOG - Watchdog, this means that the watchdog timer expired and was the cause for the board reset
Some of the newer boards / versions of software also feature a watchdog reset cause.
- TOUT - One of the i.mx6's watchdogs timed out. This means that the watchdog was not serviced within the serviceable amount of time.
- SFTW - The user caused a reset of the board (e.g. typing a "reboot" on the command line). Please see the example below:
U-Boot SPL 2014.04-00165-g9fd0ca4 (Sep 25 2014 - 14:52:25) NAND : 256 MiB U-Boot 2014.04-g6c30fe4 (Mar 27 2015 - 08:20:14) CPU: Freescale i.MX6Q rev1.2 at 792 MHz Reset cause: WDOG WDOG1 Reset cause: TOUT WDOG2 Reset cause: POR
What throughput does the PCIe lane support?
Avila / Cambria / Laguna boards support PCI Gen1 which provides a maxium theoretical bus bandwidth of 2.5Gbits/sec.
Ventana boards support PCI Gen1 due to early revisions of the boards not having an PCIe Gen2 external clock generator. Certain board revisions with an external clock generator can technically support Gen2 if it is enabled in software. See ventana/PCIe for more details.
Note that Maxium bus throughput does not account for CPU processing or bus contention from multiple masters.
Why are certain areas on the board warm with regards to temperature? Why is my board hot?
Heat is related to power. The more power the board draws, the more heat that must be dissipated.
The number one item that will be warm is the CPU. CPUs from Gateworks should all be equipped with a heatsink.
Some customers choose to use a fan but it is not required.
The Gateworks boards are rated from -40 to +85C (some processors are even higher) so this allows the boards to operate at hotter temperatures than one might expect.
The second item that will be warm will be any wireless radios that may be used. These typically consume a lot of power and thus will become warm.
Another item that is warm may be the PCIe switch (only available on certain boards). The typical power usage is appx 1.35W up to a max of appx 2.6W (max being 85% traffic). The switch does support PCIExpress Active State Power Management (ASPM)and also will power down unused SerDes lanes automatically to reduce power when possible. Some customers choose to place a heatsink on the PLX PCIe switch chip.
A successful technique has been to heatsink the processor to an exterior metal enclosure which essentially makes the entire enclosure a heatsink with lots of surface area for dissipation. This can also be done with wireless radios.
- Heat is a direct relationship with power consumption
- Heatsink the CPU to a metal enclosure for better heat dissipation
- Add a heatsink to the PCIe switch chip if desired
- Add a fan to dissipate the heat and avoid hotspots - use a fan to blow air over the board and radios to help cool them. This can be very effective even in an closed outdoor enclosure. Gateworks sells an outdoor enclosure in which there is a small fan which circulates the air inside to help even out any hot spots on the CPU and radios. This fan alone typically lowers the CPU temp by around 15C. Outdoor Enclosure
- It is possible to couple the radios to the enclosure. For doing this thermal pad material can be used. The thermal pad is applied to the top of the radio and the board is mounted so this pad then makes contact with the side of the enclosure. The pads are available in a variety of thicknesses which allows you to optimize it for your enclosure mounting. Here is a link for an example of the type of thermal pad that customers often use:
- * Gateworks Shop - Heatsinks
Please also see this wiki page for more information on Ventana Thermal Information.
How is MTBF calculated for Gateworks SBCs?
Gateworks uses the MTBF parts count method in MILHDBK-217F, Notices 1 and 2. The calculations are based upon Ground Benign environment at 55C.
- Things like connectors, MOSFET's, PLX switches, components that generate heat, drastically shorten the lifespan of the board. Some of our boards such as the GW5100 are very basic, its MTBF is calculated at 94.3 years. This may seem unrealistic but consider MTBF is biased on the board being at a constant temperature in a controlled environment, so it's not accounting for weather, salty air, dust, and other things we associate with ageing. MTBF is not intended to be a real world calculation, it's only to provide a baseline so different products can be assessed against each other in a measurable way.
Do the Gateworks boards support RTOS / Real Time OS
Gateworks does not have any direct default support for any real time operating systems. Gateworks boards are very open source and anyone is welcome to add a RTOS to Gateworks if they would like and are able.
Other third parties have explored real time operating systems on the Freescale i.MX6:
How to Improve Boot Speed / Times
Please refer to the below wiki page for speeding up the booting process, lowering the time to boot. Boot Speed Wiki Page
How to connect a LED to Ventana GPIO
Ventana GPIO typically is:
- 332 Ohm Series Resistor
- Current is rated around 12-13mA.
Read more here: ventana/DigitalIO
How Many Wireless Clients can Connect to my Access Point?
This is highly dependent on the amount of data being passed between the access point and client. If each client is streaming video from the AP, then the limit will be much smaller (estimate 3-10). If each client is only querying a small HTML webpage, this limit could be higher (estimate 15-30). There is no 'defined' limit and Gateworks recommends testing with the exact hardware (variations between processor speed, cores, memory, wireless technology, etc). One third party company has a solution to handle many clients, shown here
I see an imx-sdma message and is it an error?
It is common to see the line on Ventana boards:
[ 60.366404] imx-sdma 20ec000.sdma: external firmware not found, using ROM firmware
SDMA: Smart Dynamic Memory Allocation.
The sdma firmware was removed from our OpenWrt BSP because it is no longer necessary any longer.
It was needed for imx i2s audio in general but now the upstream kernel drivers have been modified to no longer need it. The licensing of this firmware was keeping it out of OpenWrt upstream which is why we wanted to remove it.
The message itself isn't an error. We could remove the firmware loading altogether but they haven't done that upstream in Linux so we don't think it would be right for us to do it in OpenWrt's kernel.
There are many kernel messages that sometimes are misleading, making people think there is an error when it is nothing to be concerned about.
This message may sit on the console for a little while, but if you hit the return key on your keyboard, you can quickly get a command prompt earlier.
You can try to remove this by modifying the device tree, but note Gateworks has not tried or tested this:
Here are some links you can read more about the Freescale CPU:
Why doesn't the reboot or shutdown command work on my system?
The reboot and shutdown command originated on desktop computer systems with ATX power supplies. The Gateworks boards are powered over DC and are constantly connected to the power source, thus these commands are not typically recommended on embedded systems.
Thus, the question arises, what would one expect when using the shutdown command on a Gateworks embedded board? The command itself cannot actually unplug the physical power cord.
The reboot command, in it's natural form would only reset the CPU briefly, but often so fast that the entire set of system peripherals don't properly get reset. Thus, Gateworks has steered the reboot command to use a GSC sleep for 2 seconds to act like a reset/reboot, while actually fully power cycling the main supply. This is only implemented in Gateworks BSPs that contain the proper GSC drivers and will not necessarily exist in some of the more mainline releases using mainline kernels. Read more on the GSC Reboot Wiki Page