Telemakus FAQ

Please review the questions and answers below for Telemakus product support. If your answer isn't here or covered by the product data sheet, please submit a technical inquiry.

Hardware Related Questions

  1. Can I get a demo unit to try in my lab?
  2. I received my TED6000-50 power meter but there were no instructions with it.
  3. Accuracy of the power meter is only +/-0.5dB. Is there something better?
  4. Unable to activate the TED6000.
  5. Is it possible to make a power meter that covers 5 MHz to 2 GHz, -40 dBm to +10 dBm for CATV applications?
  6. The flash drive on my TED6000-50 seems to be damaged. Could it have been damaged by ESD?
  7. What is the input VSWR for the uMeter.
  8. The TEA4000-7 data sheet mentions a USB HUB option. Is the HUB something Telemakus also sells?
  9. I am interested in the accuracy specs & frequency response (insertion loss vs. frequency & accuracy vs. frequency)of the TEA4000-7
  10. I like the performance of the (TEA4000-7) attenuator. Can I get frequency operation extended down to 1MHz?
  11. Regarding the TEA4000-7 input power, the Max Input is stated as +23dBm. However, the P1dB is then specified at +30dBm. Which is correct?
  12. Will the TEA4000-7 still work at frequencies greater than 4GHz
  13. What is the TEA4000 switching speed?
  14. What is the switching speed of the TES3000-60?
  15. Can I pulse modulate the TES3000-60 Switch?
  16. With TES3000-60, do you know how much second harmonic is generated at different input levels?
  17. What is the TES6000-30 insertion loss at 1GHz?
  18. Do you have Isolation and Insertion loss plots for the TES6000-30?
  19. Power handling capability of the TES6000.
  20. If the Telemakus Attenuator is powered down, will it maintain the attenuation value?
  21. Can the TEG2700-6 Signal Generator (1800-2700 MHz) operate at 3-4 GHz or can it be modified to cover this?
  22. What is the frequency accuracy of the TEG RF generators?
  23. We’re using Agilent 83623’s as a 2.5 GHz source because it’s very clean. I’m not sure how ‘clean’ it needs to be for our application but how does your USB device compare (TEG2700-6)?
  24. Can Telemakus make a Signal Generator with frequency range of 1200-1700MHz?
  25. Extended or alternate frequency range generators.
  26. Can Telemakus make a Vector Modulator with frequency range of 1500-1700MHz?
  27. What is the limiting factor on how many USB hubs a single PC can drive?
  28. Can you recommend a USB extender cable? Do you sell them?
  29. Do the Telemakus products have a “Certificate of Calibration”?

Software Related Questions

  1. Is there a basic tutorial for programming Telemakus devices?
  2. Can you provide sample code, an API or SDK in .NET format
  3. Does the TED6000-50 have a programming API available so that a custom application can gather data?
  4. Can the TES3000-60 be controlled via USB by a "user" program?
  5. Do the Telemakus test products support Linux?
  6. Is it possible to control the TES6000-30 USB RF SWITCH with any programming language, for example LabVIEW?
  7. Can I use the device driver with .dll file in MatLab and C#?
  8. Will the Telemakus API work with the Python programming language?
  9. How do I run two or more devices on the same computer?
  10. Problem running two attenuators with customer program.
  11. I’m having issues with the Visual Basic driver while running multiple devices. Can you help?
  12. Is there a way to use the Telemakus products with existing GPIB instruments?
  13. I’m trying to use the TED6000-50 on an older computer and get a message to update my system.
  14. TEA4000-7 is identified very slowly using W7 64-Bit

Hardware Related Answers

1. Can I get a demo unit to try in my lab?

Answer: The biggest concern with sampling test equipment is the physical condition upon its return. With low cost test equipment such as Telemakus, the best way to get a sample is to provide a purchase order or credit card number with a contingency. For example, you might arrange with the distributor for a 15 day “trial”. If you like the device, you keep it and pay the invoice or allow your card to be charged. If not, you can return it for a restocking fee that will cover the cost of retest/recertifying performance.

Note that retest/recertification and restocking is an average cost of ~$60 but varies depending on the device. If the housing is damaged or cracked, then retest/recertification could be as much as the cost of a new unit.

2. I received my TED6000-50 power meter but there were no instructions with it.

Answer: There should have been a blue instruction card packaged with the device describing the step-by-step operation on how to install the product. Page 1 describes how to attach the device to the PC. Page 2 (back page) describes how to load and run the GUI.

This information is also presented in a "readme.txt" file located on the product's flash drive so once you plug in the device, you can access the readme.txt file.

3. Accuracy of the power meter is only +/-0.5dB. Is there something better?

+/- 0.5dB of accuracy is not much better than a spectrum analyzer. Since we have to tune up our transmitters for power, every 0.1dB is important.

Answer: The Telemakus devices will not replace a high end power meter costing 10x the price and they’re not meant to. If high level accuracy is required, then go with a more expensive, metrology grade product. FYI, metrology grade attenuators should also be used in the test set up as well. A typical 5W attenuator will have +/-0.5dB accuracy.

Feedback from an existing customer:

“I just talked to the guys at XXX on Thursday about the RMS detector and digital attenuator.
Both have worked great. They said the RMS detector was dead on with their expensive test equipment and liked the 0.25 dB steps of the digital attenuator.
They are looking forward to buying the signal source when it is available.”

4. Unable to activate the TED6000.

We recently purchased a TED6000 power meter from RFMW for assessment in a current project.
Although the device appears to have successfully installed itself on the computer, we are unable to activate it. There was no software or instructions with the device; we assumed it would operate automatically upon installation, but not so! Your data sheet suggests software is available from your website but no download is evident. Can you advise please?

Answer: Sorry to hear you are having difficulties installing with the TED6000.

From your e-mail, it sounds like the device correctly registered itself with Windows and all that remains is for you to load and activate the Graphical User Interface (GUI) software located on the device flash drive.

There should have been a blue instruction card packaged with the device describing the step-by-step operation on how to install the product. Page 1 describes how to attach the device to the PC. Page 2 (back page) describes how to load and run the GUI.

This information is also presented in a "readme.txt" file located on the product's flash drive and is copied below.

User Interface (GUI)
Software Installation

1) Complete the installation instructions for the device before installing the GUI
2) Open the My Computer folder on the PC and locate the device name under the Removable Storage Devices.
3) Open the device disk by double-clicking on its name or by using Windows Explorer
4) Locate the installation file named “Install <devicename>.msi” and double-click on that file to begin the installation process. The Installer program will take you through the remaining installation steps.
5) Start the program by clicking on the shortcut installed on the PC desktop or on the Start Menu

Problems: email – Support@Telemakus.com

5. Is it possible to make a power meter that covers 5 MHz to 2 GHz, -40 dBm to +10 dBm for CATV applications?

Answer: After a quick review of available detectors it looks like 5MHZ to 2GHz is possible but would not be RMS and so accuracy would be lower. This would require a new design as the existing TED6000-50 can not be modified to work below 50MHz. Depending on the quantity required; we could make this a standard product

6. The flash drive on my TED6000-50 seems to be damaged. Could it have been damaged by ESD?

Answer: After calibration, Telemakus products are packaged in protective, anti-static bags and placed in padded, anti-static boxes for shipping. They are stored in the warehouse at RFMW until shipped to a customer order.

RFMW does not remove the devices from their protective bags/boxes unless physical damage to the box is detected at incoming inspection. If the contents require inspection, the receiving and shipping areas at RFMW are static controlled environments with conductive waxed floors and trained personell wearing ESD smocks and conductive wrist and shoe straps. And outwardly damaged devices would be returned to the manufacturer.

Note that Telemakus has performed extensive and abusive tests on their products (such as unplugging in the middle of operations etc.) and haven't been able to force a failure yet.

RESOLUTION - Thank you for the help. The problem was that I didn't rename the volume properly when formatting it. But everything seems to be working in order now.

7. What is the input VSWR for the uMeter.

Answer: The nominal return loss is 20dB or VSWR of 1.2:1.

8. The TEA4000-7 data sheet mentions a USB HUB option. Is the HUB something Telemakus also sells?

Answer: Regarding USB Hubs, they are not all created equal. From extensive testing, we've found two models providing good results; TheT-HUB4-1 provides 3 additional USB connections. If more ports are needed, theT-HUB7-1 provides 7 output ports and uses an external power supply to drive the needed current for industrial applications. HUBs can be obtained with 16+ ports or HUBs can be cascaded. For example 2 of the T-HUB4-1 HUBs would provide 7 ports when cascaded.

9. I am interested in the accuracy specs & frequency response (insertion loss vs. frequency & accuracy vs. frequency)of the TEA4000-7

Answer: The TEA4000_7 includes a plot of Insertion Loss vs Frequency for the 0.0dB setting located on the flashdrive of the unit. You can access this by going to My Computer on your PC and double clicking on the drive named TEA4000_7.

Attenuation Accuracy is not a published specification for the unit but typically will be about +/-(0.2 + 2%) of the Attenuation value in dB. So the total insertion loss of the unit at 2.5GHz with a setting of 20dB could be estimated as:

Insertion Loss for 0.0dB @ 2.5GHz (from graph) + 20dB +/-(0.2 + 0.02*20)dB

10. I like the performance of the (TEA4000-7) attenuator. Can I get frequency operation extended down to 1MHz?

Answer: Yes, most of the Telemakus devices can be tuned for varied or additional frequency coverage. There may be performance trade-offs and customer specific alterations require a minimum order of 4-5 units depending on the device. This eliminates NRE costs.

The TEA4000-7 tuned down to 1MHz is available as a standard part number TEA4000-7W

11. Regarding the TEA4000-7 input power, the Max Input is stated as +23dBm. However, the P1dB is then specified at +30dBm. Which is correct?

Answer: Regarding the power handling; the total power dissipation for the part is limited by maximum junction temperature and is therefore a function of average power. Distortion of RF signals is caused by the compression in the device and therefore is specified by P1dB and IIP3. If a high peak to average signal such as WCDMA is applied to the attenuator the maximum average power will be 23dBm but the peaks in the signal must also be kept below 30dBm to avoid compression.

12. Will the TEA4000-7 still work at frequencies greater than 4GHz

Answer: Yes, the TEA4000-7 is meaured to 4GHz but can be used up to 6GHz with reduced performance. Insertion loss, attenuation accuracy and return loss all degrade and are not tested above 4GHz. For operation up to 8GHz, we recommend the TEA8000-6

13. What is the TEA4000 switching speed?.

Answer: This is an interesting case study. Telemakus devices are the ideal choice for developing a low cost Fade Simulator for production testing.

There is more than one way to tackle this application depending on the level of control required.

1) The simplest approach would be to use the TEA4000_7 Attenuator and make consecutive function calls to alternate the Attenuator setting between 0dB and 31.5dB Max. This approach has been bench marked as part of the Power Leveling Loop in the Telemakus Scalar Network Analyzer software application. The switching time is approximately 3 - 5ms on average but is highly dependent on the Windows operating system and Windows moment to moment activities. The interval could jump to a few hundred milliseconds briefly if Windows got involved with a higher priority task such as memory management.

2) A more precise approach might be to use the TES7000_50 RF Switch, with its programmable modulation control, to switch between a high level and low level test signal generated from a power splitter or coupler and a fixed pad. The TES7000_50 can generate repetitive switched pulses with precise pulse widths from 250ns to 8 seconds in 250ns increments. The pulse repetition rate can also be precisely controlled over the same interval.

3) The best of both worlds would be to replace the fixed pad in number 2 above with the TEA4000_7 Attenuator. Then you would have the capability to vary both the RF power of the fade test signal as well as the pulse width and repetition rate of the fade test signal under precise control.

14. What is the switching speed of the TES3000-60?

Answer: The TES3000-60 switching speed is rated at 5uS. This is the 10 to 90% rise or fall time on the edge of a RF transition and applies to any transition between two states e.g. RFC-RF1 to RFC-RF2 or both ports isolated to either RFC-RF1 or RFC-RF2. If faster switching time is required, the TES6000-30 has a 30nS 10-90% transition but lower isolation and is reflective at all ports rather than absorptive.

15. Can I pulse modulate the TES3000-60 Switch? I want to create a pulse generator using the TEG2700-6 and a switch.

Answer: No, not in it's currrent configuration. However, the TES6000-30 has pulse modulation capability and covers most of the same frequency range (100 to 6000 MHz). The min pulse width is 125nS.

16. With TES3000-60, do you know how much second harmonic is generated at different input levels?

Answer: We do not collect data on the second harmonic performance of these devices so there are no graphs or charts. However, it is possible to estimate the Second Harmonic value using the Output Second Order Intercept point for the device.

The Output Second Order Intercept point (OSOI also called IP2) for this device is not given on the Telemakus datasheet but is estimated to be +80dBm.

The formula that allows you to predict the Second Harmonic (SH) level in dBc (dB below the carrier) as a function of the output power (Pout) at the fundamental frequency is then given as:

 SHdBc =OSOIdBm -Pout,fund,dBm

where: Pout,fund,dBm is the desired output power at the fundamental frequency in dBm

Example:

If my desired output power is +10dBm at 1000MHz then for the TES3000_60 with IP2 of +80dBm, the estimated Second Harmonic level would be

SHdBc = +80dBm - (+10dBm) = 70dBc or 70dB below the fundamental or -60dBm at 2000MHz.

17. What is the TES6000-30 insertion loss at 1GHz?

Answer: Specified insertion loss is 2.0dB max. However, at 1GHz, typical insertion loss is approximately 0.85dB.

18. Do you have Isolation and Insertion loss plots for the TES6000-30?

Answer: Yes, the TES6000-30 Isolation plot can be viewed HERE. The TES6000-30 Insertion Loss plot can be viewed HERE.

19. Power handling capability of the TES6000.

We are looking for a solution whereby we can switch the RF output from a modem to one of two antennas and we wish to control the RF switch via a USB port.

The TES6000 looks like an ideal solution however I have some concerns regarding the input power. The modem can output up to 2W (33dBm) in the GSM band and the max. input specified for the TES3000 is 23dBm (0.25W). However the TES6000 datasheet shows a continuous wave power of 33dBm is allowable. With power levels in mind would the TES6000 be suitable for our application?

Answer: Thank you for your inquiry.
You are right, the TES3000-60 has a max power of 23dBm due to the termination internal to the device. The TES6000-30 has a P1dB of 33dBm but has no internal termination and is therefore reflective. The real limit is power dissipation in the switch which is limited to 0.8W. If you are using a pulsed modem with a peak power of 2W then the loss of 1dB at 900MHz will create a dissipation of 0.2W and will therefore be well within the limit.

The switch will dissipate more power during switching. Ideally you should switch when the RF is OFF.

20. If the Telemakus Attenuator is powered down, will it maintain the attenuation value?

Answer: The Telemakus Digital Step Attenuator (DSA) is powered by the USB port. If disconnected from the host PC, the DSA goes to an unpowered attenuation state of approximately 10 to 15 dB of attenuation. If the DSA is connected to a hub, the hub will supply voltage and the DSA will stay at its current settings even when the host PC is disconnected (as long as there's no interruption of power to the hub). If power to the hub is lost and then reestablished, the DSA goes to its maximum attenuation value of 31.75 dB.

21. Can the TEG2700-6 Signal Generator (1800-2700 MHz) operate at 3-4 GHz or can it be modified to cover this?

Answer: 3 - 4 GHz is within the range of the existing design. Telemakus would have to look at power output and change the harmonic filtering. This would be a customer specific design and require a min order of 4-5 pieces.

Update: Other models are availalble with various frequency options as shown below. The TEG4000-1 covers the requirement:

TEG250-15 (140 - 250 MHz)
TEG1000-10 (700 - 1000 MHz)
TEG2700-6 (1.8 - 2.7 GHz)
TEG3500-8 (2.7 - 3.5 GHz)
TEG4000-1 (0.2 - 4.0 GHz)
TEG10200-1 (9.3 - 10.2 GHz)
TEG26500-5 (24 - 26.5 GHz)

22. What is the frequency accuracy of the TEG RF generators?

Answer: All the TEG family generators use the same 2.5ppm, 10MHz reference oscillator with the exception of the TEG10200-1 and TEG26500-5 which use a 0.5ppm reference oscillator. To calculate the worst case frequency error over temperature at any given frequency, divide the frequency of operation in GHz by 1 million and multiply by 2.5.
Example: 2GHz/1M x 2.5 = 5KHz
For the TEG10200-1 and TEG26500-5 at 0.5ppm, an example would be as follows:
10GHz/1M x 0.5 = 5KHz

If the generator is connected to a TEX doubler, the worst case frequency error over temperature at any given frequency would double while operating in the 2X mode.

23. We’re using Agilent 83623’s as a 2.5 GHz source because it’s very clean. I’m not sure how ‘clean’ it needs to be for our application but how does your USB device compare (TEG2700-6)?

Answer:
Spurs: The TEG2700_6 beats the 83623 hands down at 2.5GHz (-80dBc vs -60dBc).

Phase Noise: The two are comparable for Phase Noise at 10kHz and 100kHz offset, with the 83623 being better below 10kHz offset (it uses a more stable reference)

Harmonics: The 83623 wins here (-20dB compared to -30dB for the 2nd Harmonic) We can do a special that would trade a few dB Ouput Power to be <-30dB

Freqency Step Resolution: Both units are 1kHz (unless you have the 1Hz 83623B model with option for high resolution)

Pricing: The TEG2700_6 is about 10x less expensive than a used 83623. (Agilent can't touch this for Price/Performance)

24. Can Telemakus make a Signal Generator with frequency range of 1200-1700MHz?

Answer: Yes, 1200-1700MHz is within the range. Performance would be similar to TEG2700 with typical output power of 8dBm but 2nd harmonics would be about -10dB due to the internal filtering. An external filter can be used by the customer if harmonics present a problem. Part number will be TEG1700-C. Customer specific alterations require a minimum order quantity depending on the device. This eliminates NRE costs.

Update: TheTEG4000-1 covers this frequency band.

25. Extended or alternate frequency range generators.

I was wondering if Telemakus can provide synthesizers which operate in slightly different frequencies than the TEG2700-6 operates (1.8-2.7GHz). I am looking into other synthesizers that can go up to 2.9GHz. Can the TEG2700 be operated out of the box up to 2.9GHz with some performance degradation? Alternatively can Telemakus provide another synthesizer (maybe custom) that will work up to roughly 3GHz?

Answer: The on-board firmware will preclude use of the TEG2700 above 2.7GHz. However, with firmware and component modifications, the basic Telemakus generators can be extended up to 3GHz.

The output power will degrade slightly, and harmonics will be an issue as 2x 1.8GHz, 3.6GHz will be that much closer to 3GHz limiting the filtering designed into the product. If we were to also raise the lower frequency, 1.8GHz, to approx 2.2GHz this would allow us more flexibility.

26. Can Telemakus make a Vector Modulator with frequency range of 1500-1700MHz?

Answer: No, The vector modulators being used internally are band specific and will not work outside the specified frequency.

27. What is the limiting factor on how many USB hubs a single PC can drive?

Answer: In theory you can have 128 USB devices on a single PC. However, the HUB’s also count as devices. We have yet to have an issue but have only had 3 HUBs fully loaded. Using our 7 port HUBs and cascading them (i.e. each HUB connected in series), you can effectively have six actual devices per HUB and 128/6 = 21. 21 HUBs leaves 128-21= 107 devices. If you also have printers, keyboards, mice and other USB devices then these all subtract from this total. The host PC has to service all these devices on a time shared basis. Windows manages this itself and uses a complex set of priorities based on the types of devices and the bandwidth required for each one. Another factor is current used. Our HUBs are self powered and can support 0.5A per device. Other HUBs can only support 2A total and so this would restrict the number if devices before the supply fails or the PC crashes. We have seen both occur when using other HUBs.

28. Can you recommend a USB extender cable? Do you sell them?

Answer: Yes, Telemakus has tested multiple USB cables and found many of them inferior. Therefore they have sourced their own USB extender cables, the T-CABLE-3, avaialble from RFMW. If a customer decides to use his own extender cable, they should ensure a solid connection to the product and PC as loose connections could potentially damage the devices. 

29. Do the Telemakus products have a “Certificate of Calibration”?

A customer running a certified lab with ISO/IEC 17025:2005 wants to know if the Telemakus power meter comes with a “certificate of calibration”. If so, he would like to see a copy of the cert to see if he can use the power meter in his lab.

Answer: At the present time, Telemakus does not supply a certificate of calibration with the unit and do not make any claims to follow any particular international metrological standards (all of these things add cost).

They are however, calibrating the unit against other equipment that is calibrated and maintained following those standards. This may qualify Telemakus to eventually claim to be a lower tier calibration facility that can issue such certifications but at the present time, on paper, they do not have authority to do so.

Most ISO companies allow the use of "uncalibrated" equipment (eg. power supplies) provided that the equipment is used with other calibrated equipment or calibrated following an internally written process that demonstrates the device meets its published specs.

There are some advantages to being able to produce "Pedigree" paperwork for the device. And Telemakus might offer a certifcation in the future as an add-on cost (by using an outside certified calibration lab). But the specification of +/- 0.5dB accuracy would preclude use of the device in most high accuracy applications demanding tight tolerances anyway. These are some of the tradeoffs between a $300 vs a $3000 device.

Software Related Answers

1. Is there a basic tutorial for programming Telemakus devices?

Answer: Yes. Basic programming information is covered in an application note - TeleApp #004 Programming Interface for the Telemakus USB Devices.

2. Can you provide sample code, an API or SDK in .NET format

Answer: Yes, sample code is available upon request for customers using Telemakus test devices. Model number and serial number must be included when requesting sample code atsupport@telemakus.com Custom software is also available on a contract engineering basis.

3. Does the TED6000-50 have a programming API available so that a custom application can gather data?

Answer: As of April 2010, Telemakus devices will include the API library. An upgraded GUI is free for customers with older products. Contact support@telemakus.com with the Model Number and the Serial Number's for the units to be upgraded. The upgrade software will then be delivered via e-mail.

4. Can the TES3000-60 be controlled via USB by a "user" program?

Eg: do you publish the protocol for controlling the switch so that I can control it from my application on a PC? (I don't want to use your "graphic interface")

Answer: Telemakus products can be controlled from PC programs using .NET compatible drivers. Sample programs are available from Telemakus LLC.

5. Do the Telemakus test products support Linux?

Answer: Telemakus products do not currently support Linux operating systems. However, the USB interface is standard. 

6. Is it possible to control the TES6000-30 USB RF SWITCH with any programming language, for example LabVIEW?

Answer: Yes it is possible to interface all Telemakus devices to LabView. Telemakus devices behave as .NET objects. This allows LabView to communicate with the devices by using the .NET support features in LabView.

7. Can I use the device driver with .dll file in MatLab and C#?

Thank you for driver , I am in vacation now so I will try the driver only next week.
I can you use with dll file in Matlab and C#?

Answer: Yes, the interface to Matlab is available using the API provided with the device. This file and a Visual Studio 2008 example program are included with the device. The example program will provide some additional insight into the usage of the API. To utilize the driver in Matlab refer to the link below which describes using .NET assemblies in Matlab:

http://www.mathworks.com/help/techdoc/matlab_external/brpb5k6-1.html

8. Will the Telemakus API work with the Python programming language?

Answer: It seems the established API interface which works across most all development tools supporting .NET sometimes fails with the Python tool even though it supports .NET. Existing web discussions show that Python does not always integrate well with .NET. It seems some compilers are not able to locate the information needed to link the API library to an application. In light of this, we have to answer "Not at this this time, but the possibility is being investigated".

9. How do I run two or more devices on the same computer?

Answer: You must launch two copies of the GUI software in Windows. Here are the steps to follow:

  1. Plug both devices into the USB ports of the PC

  2. Launch the first copy of the GUI software.

  3. The first copy will prompt the user to connect to the first device. The user should answer YES.

  4. Launch the second copy of the GUI.

  5. The second copy of the GUI will prompt the user to also connect to the first device. The user should answer NO. The GUI software will then prompt the user to connect to the second device. The user should answer YES.

We have ashort visual presentation on this procedure.

10. Problem running two attenuators with customer program.

I have problem to use with your digital attenuator in our system.
With your program I can control on 2 different attenuator, but when I try to use with your dll in my code I can control only 1 attenuator.
I attached two simple code in VB, first need to control on attenuator SN:0002 and the second need to control on attenuator SN:0004.
When I run this program I can only control in attenuator SN:0002.
Please help to understand what is the problem.

RESOLUTION: This concern involved issues with early versions of the API's where Windows did not correctly recognize multiple devices of the same type attached at the same time. The problem has been corrected in the latest release of the API libraries for all Telemakus products. Customers reporting any problems like these should contact Telemakus support for a free API upgrade which will be delivered by e-mail. 

11. I’m having issues with the Visual Basic driver while running multiple devices. Can you help?

Answer: It seems that Windows has many surprises when using multiple devices on a single PC. The inter-process messaging took longer to work out than we originally thought but here it is.

The driver file (TEA4000_W_drv.dll) works well when it is used correctly but the error handling routines still have some bugs. In particular, if you attempt to access a unit using a Serial Number that does not exist, Windows will throw an exception error. We are trying to understand this problem. It has to do with the method that Windows disposes of unused objects during the closing process. That issue should not be a problem for you if you always reference Serial Numbers that are actually attached to the PC.

RESOLUTION: This concern involved issues with early versions of the API's where Windows did not correctly recognize multiple devices of the same type attached at the same time. The problem has been corrected in the latest release of the API libraries for all Telemakus products. Customers reporting any problems like these should contact Telemakus support for a free API upgrade which will be delivered by e-mail.   

12. Is there a way to use the Telemakus products with existing GPIB instruments?

“How do we control our existing gear via USB, which has old GPIBs. What I am looking for is a device which plugs into the old GPIB, but converts immediately into USB, so we could avoid the huge GPIB cables and the GPIB interface cards in the PC. The Labview guys have something, but I need to study it better.”

Answer: National Instrument, Agilent and a couple of others sell them for about $500.
We use one to interface to older instruments such as the Agilent 82357A/B.
It's amazing that one can purchase 2 of our newer instruments for nearly the same price as it takes to talk to one of the older ones.

13. I’m trying to use the TED6000-50 on an older computer and get a message to update my system.

Answer: Telemakus devices contain flash memory with the software used to drive them. The installer will check to see if Microsoft .NET 3.5 or later is installed on the PC, if not, the user will be directed to the Microsoft web page to download the FREE copy (Microsoft .NET download page). Most newer PC's will all ready have this installed, older PC's will not (version 2.0 is typically found but no harm in upgrading)

The Telemakus flash memory contains a Readme.txt file that explains the normal installation process for the device.

14. TEA4000-7 is identified very slowly using W7 64-Bit.

Question: I am using Windows7 64bits. My current main problem with TEA4000-7 is it takes too long to let the windows7 find the device. It takes about a few minutes.After plugging in, I have to wait for a quite while before it starts working. Why it is so slow and is there any solution?

Answer: The slownesss you are experiencing during enumeration is a problem with Windows 7. For some unknown reason W7 delays the attachment of the device. XP does not exhibit this behaviour. We have been in contact with Microsoft on this problem and they have assigned someone to look into it so we are hoping for a resolution. Our tracing shows that W7 completes all of the required USB communications to enumerate the device and then just sits there. Noone knows why as yet. I suspect something gets stuck and eventually timesout to allow the process to continue but Microsoft has not yet been able to determine a solution. They requested one of our devices be sent to Redmond Washington so they could work on it. They have the device, now we have to see if they can provide a solution.

If enumeration speed is essential, then the best solution I can offer at the moment is to run W7 in XP compatibility mode supported by Microsoft.