GS-MAX-8000

[Sesselmann]

Hi All,

We have recently added a new product, the GS-MAX-8000 this is not a sound card spectrometer it is a high speed digital spectrometer, meaning it has a microprocessor on the board that does all the MCA work and outputs a complete spectrum.

We have built it into the same quality enclosure as the GS-PRO-V5, but that's where the similarity ends. The GS-MAX-8000 communicates via USB Serial UART connection and it is not compatible with PRA, but it works great with Becqmoni (Atom) and IMPULSE.

The main advantage offered by the GS-MAX-8000 is it's speed, it can record a spectrum at up to 100,000 cps., essential for large detectors 3" and up where count rates might exceed the limit of the GS-PRO-V5.

https://www.gammaspectacular.com/blue/g ... s-max-8000


Steven

[Rob Tayloe]

hi Steven,
I received my GS-Max-8000 yesterday. I have not yet tried to use it, but rather perused the supplied manual. It seems that there are a number of "codes" that are used to communicate with the device. Does one use some sort of "terminal" program and use ASCII to send "codes" to the device? I recall the early Hayes 300 baud modems had the "AT.." codes used to communicate with the modem via an RS-232 cable. Is communication between the PC and the GS-Max-8000 done in a similar manner? It is my intent to use the IMPULSE program for gamma spectrometry with the GS-MAX-8000.

Also, is the signal port able to be used to send a pulse to an oscilloscope similar to the GS-USB-Pro devices?

Thanks!

[Sesselmann]

Hi Rob,

Good idea to post your question here 👍

It seems that there are a number of "codes" that are used to communicate with the device.

Yes that right, and in the software "impulse" and "Becqmoni" you will find that some of the commands have been pre programmed as buttons or functions, where other less common commands need to be entered via a command input field. It is advisable to be careful when sending commands to the device as some commands can put the devise into a different mode and render it unable to function as a spectrometer. Of course it can be restored again with the correct command.

In Impulse I have deliberately disallowed commands that mess up the functions, but Becqmoni will allow all commands to be sent.

You should never need to do anything via the commands prompt or terminal window unless you are a hacker and really want to 😝

I recall the early Hayes 300 baud modems had the "AT.." codes used to communicate with the modem via an RS-232 cable. Is communication between the PC and the GS-Max-8000 done in a similar manner?

Communication with the GS MAX is via USB Serial connection with UART protocol at a blisteringly fast 600,000 baud, so yes, similar but much faster.

It is my intent to use the IMPULSE program for gamma spectrometry with the GS-MAX-8000.

I just published Impulse 2.2.6 and it should work well with GS-MAX, but I encourage you to try Becqmoni as well.

Also, is the signal port able to be used to send a pulse to an oscilloscope similar to the GS-USB-Pro devices?

No, despite it's appearance the signal port on the GS-MAX is actually for the temperature probe, so no output there.

You can view the pulse in Impulse, and also in Becqmoni by sending the right command.

Let us know how you go or if you have further questions.

Steven

[Rob Tayloe]

Hi Steven,
Today I attempted to use the GS-MAX-8000 for the first time. I downloaded the current version of Impulse (2.2.7). After a few minutes fooling around, I was not getting success. I would like to request more instruction, perhaps even a video tutorial. I am attaching a couple of screen shots from my Windows 11 laptop. Using the pull-down menu I selected "com3"; the default settings are shown (9600, 8-N-1). You indicated that the MAX-8000 communicates very fast, but it seems that one must manually configure the port, no?

Upon plugging the USB cable in the illuminated window displayed 609. Is this the voltage setting as was the case with the GP-PRO? The "U" (or is it "-U" ?) setting has a range from 0-255; how does one select a voltage of say, 900 volts?
Presumably I will want to set the MCA mode?

I am looking forward to using this device. I find your instructive videos to be most useful in causing the light bulb over my head to illuminate [I don't know how well this expression translates, but my meaning is "to more fully grasp the operational methodology".]

Thanks!
Rob Tayloe

[Sesselmann]

Rob,

Thanks for your query and sorry for slow reply, I have been renovating my workshop with new epoxy floor, so everything had to come out and back.

Connecting a GS-MAX with Impulse should be simple, I like to say "Any device that needs a manual, is broken !!"

1) Connect the GS-MAX-8000 to your PC (USB)
Windows should immediately locate and install the driver without you having to do anything, it might take a few minutes to download and install.
However Windows doesn't alway work, if so it may need to be manually installed. https://ftdichip.com/drivers/vcp-drivers/

2) Open Impulse
Impulse should automatically open up on Tab1 where you select the device. Select the serial device and refresh your browser.
Note: Impulse runs in a browser - some fields need a browser refresh in order to update.

Start on tab1

3) Optional - Check and update your devise settings
Clicking the submit button without any command input, fetches all devise settings.
You can change the voltage in approximately 8 Volt steps by sending the command -U000 to -U254

Inspect device data

4) Look at the raw pulse
This function allows you to look at the pulse and see the sample points. Your spectrometer has been pre adjusted for NaI(Tl) detectors.
Pulse rise -ris
Pulse fall -fall
Note: The pulse rise time and fall time is specific to crystal type and will need adjusting when switching between NaI(Tl) and Csi(Tl), just count the number of samples up to the peak and down to the tail.

Look at the pulse

5) Now go to spectrum tab, Name your file and click start to record a spectrum.
Most of the functions on the spectrum page should be obvious, but if in doubt, look it up in the manual on the last tab.

Spectrum

Bugs 🐞
Please notify me if you run into any bugs.
One minor bug I am already aware of in v2.2.7 is when exporting a file to csv it does not check if another file exists with the same name, so it simply fails to write it.


Good luck..


Steven

[Sesselmann]

You indicated that the MAX-8000 communicates very fast, but it seems that one must manually configure the port, no?

The GS-MAX communication speed should be 600,000 Baud, normally you should not have to set this manually.

Upon plugging the USB cable in the illuminated window displayed 609. Is this the voltage setting as was the case with the GP-PRO?

Yes, consistent with the GS-PRO, the GS-MAX LED display also shows voltage.

The "U" (or is it "-U" ?) setting has a range from 0-255; how does one select a voltage of say, 900 volts?

The command for changing the voltage is "-U000" to "-U254" in approximately 8V steps

NOTE: The trimmer potentiometer on the GS-MAX is for pulse shape and should not require adjusting (don't confuse it for a voltage setting like on the GS-PRO)

[Rob Tayloe]

Hi Steven,
I am still struggling with the GS-MAX-8000. I installed the FTDI driver and reset my laptop (Windows 11). Upon starting Impulse 2.2.7 the GS-MAX-8000 was recognized. The voltage was shown as 609. I wished to have 900 volts for the CsI detector that I was going to use. If the voltage is set in 8 volt steps, I figured to start with a value of 100 to get around 800 volts. I entered a command "-U100" and hit submit. The voltage changed to 1231 volts, which was higher than I wanted. I tried to enter a lower value, e.g., 75 using "-U075" and "-U75" but there was no change to the displayed voltage. Thus, until I can set the desired voltage, the GS-MAX-8000 is not useful. Attached is a screen shot showing the settings.

[Rob Tayloe]

Last night I downloaded the version 2.2.7 of Impulse for the mac. I installed Impulse on my macbook pro and connected the GS-MAX-8000. It took a great many attempts to change the displayed voltage. Multiple attempts were made entering "-U000" and variations "_U 00", "-u000","-U 00", etc. using the "enter" key as well as clicking on the "submit" button. Finally the device voltage changed to 400 volts from the "0" setting. I then spent many attempts to get a setting of "75" (voltage still too high), then "50", back to "0", then to "55" (with a voltage of about 870). This took a couple of hours and I still wasn't at the desired voltage. I finally gave up. I guess that I would have expected the command communication to be somewhat more effective and efficient with the mac. Perhaps there is some communications issue that is easily resolvable. This iteration to find the desired voltage setting is ineffective. I was using the supplied USB cables with the GS-MAX-8000.

[Rob Tayloe]

This morning I took my Windows 11 laptop and installed Becqmoni from your downloads page. Installation using setup.exe was straightforward. I was using a NaI scintillator which required 700 volts. I was able to enter the "-Uxxx" commands very simply and quickly to set the voltage to 701 volts (which ended up being "-U036"). Other aspects of using Becqmoni are not intuitive to me and will require considerable time to become comfortable with its use. I was able to acquire a Cs137 spectrum after some experimentation. My preference is to use software with which I have become more familiar. It would appear that Impulse may have some issues in communicating with the GS-MAX-8000.

[Sesselmann]

Rob,

Good news that you were able to set the voltage using Becqmoni. I agree it is a but unintuitive to set the voltage via commands, I much prefer a simple potentiometer myself, but I suppose I could print a table in the manual showing the approximate voltage for each setting.

-000 = 500
-001 = 508
-002 = 516 etc..

Not sure why you were experiencing communication issues with Impulse, I will need to investigate this more closely. I may have to add some delay between consecutive commands to make the device responds before another command is sent. Sounds like we have some kind of data collision. Were you trying to change the voltage whilst the device was running a spectrum?

In any case I need to make the interface more robust, so thanks for the feedback.

Steven