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Need personal use info on a DDS function generator.

J

Jamie

Jan 1, 1970
0
We need 4 arbitrary capable function generators
What I've found that looks interesting so far.

http://www.tequipment.net/BK4045.html

We need to use the arbitrary function to control
a steering system in irradiation units so that we
can guide the electron beam around a couple of obstacles
that are causing some ripples in the path during the sweep.

I want to attach a arbitrary generator to the steering
amplifiers (x,y) and have it gated from the scan signal.

I would like to know how well the arbitrary editing performs
on this unit, before we go out and buy a few.

I need to generate at least 2 sinusoidal in a DC offset
curve. The sweep time for the total pattern will be 100Hz
or 200 Hz and we'll use the computer system to talk to it
when the operator is setting a job.

Do you think this unit gives enough way points in a 200 Hz
time window to generate 2 sins/cos on a DC offset ramp ?
And how reliable do you think this unit is?

What we have now on one process is a Atmega with multiple
DAC(PWM) outputs driving differential amps into a summer. We talk to
this uC via RS-232. it works but it's custom made in house (by me)
and they want to tool the machines with off the shelve replacement
components.


Thanks.

http://webpages.charter.net/jamie_5"
 
J

Jamie

Jan 1, 1970
0
John said:
I designed this a few months ago...

http://www.highlandtechnology.com/DSS/T344DS.html

It's nice and small, good for embedded stuff. We have another version
that has four more internal arb channels that can modulate or sum into
the main four outputs, to do am/fm/chirps/stuff like that.

John

That's nice, It may even be a better choice considering the space we
have to mount it.

Is this unit supplied with programming doc's so that it can be
incorporated into a software package via the serial port or is there
a driver (DLL file) that must be included and thus linked from there
or some BDE, COM interface?





http://webpages.charter.net/jamie_5"
 
J

Jamie

Jan 1, 1970
0
John said:
The communications is all simple ascii commands, so you'd probably
write appropriate code into your application. All you have to do is
open a comm port and talk. Things like Hyperterminal work fine for
playing, and it has built-in Help. We do have a test program (in
PowerBasic) and a sort of virtual instrument Windows thing (java)
which we give away, sources included, but most users write their own
stuff into their overall application.

Here's the manual, 5 megabytes or so:

ftp://jjlarkin.lmi.net/T346ManA2.pdf

If it looks useful, email me and maybe arrange for a loaner.

jjlarkin atsign highlandtechnology dotto com

This was a lot of fun to do, especially the T346 version that has all
the modulations. We got to re-live a lot of the "Signals and Systems"
stuff we took in school. I did the hardware design and wrote the
internal firmware, and my super FPGA guy did all the core stuff in a
Spartan3 and persuaded it all to run at 128 MHz.

We were in trouble on the DAC lowpass filters until we bought the
Nuhertz software, which designed an amazing LC lowpass filter in a few
minutes. That guy is really smart, but also very, very crabby.

John
Thanks, I just down loaded it, I'll take this to work tomorrow and we'll
all have a look at it.


http://webpages.charter.net/jamie_5"
 
W

Winfield Hill

Jan 1, 1970
0
John said:
I designed this a few months ago...
 http://www.highlandtechnology.com/DSS/T344DS.html

It's nice and small, good for embedded stuff. We have another version
that has four more internal arb channels that can modulate or sum into
the main four outputs, to do am/fm/chirps/stuff like that.

John, how come you don't have a pdf-file datasheet yet?

What do the T344 and T346 cost? I want one, a T346 if
we can afford it! I enjoyed the photo of the pcb you put up.
 
W

Winfield Hill

Jan 1, 1970
0
Winfield said:
 John, how come you don't have a pdf-file datasheet yet?

 What do the T344 and T346 cost?   I want one, a T346 if
 we can afford it!   I enjoyed the photo of the pcb you put up.

How much of the timing occurs in the 68332, and how much
in the FPGA? I can see you can design the circuit and lay
out a pcb, etc., but a huge task lies on the uP and FPGA
programming and debugging. Not to mention writing the
manual and sales literature.
 
W

Winfield Hill

Jan 1, 1970
0
John said:
Rob, my FPGA guy, did a lot of the heavy lifting on this one, making
everything work at 128 MHz. The interpolation was a nice touch. We
negotiated the architecture together. I did the schematic, the 68K
firmware (almost 7k lines of assembly, maybe 3 weeks total), the
PC-resident test/cal program (a couple of days, PowerBasic), and the
manual (another week or so.) We had a friend do the Java Win/Linux
virtual instrument demo thing for $10K.

The FPGA does all the realtime stuff, and the 68K does the serial
comm, command parsing (438 distinct serial commands!), waveform
loading, BIST, configures the fpga, stuff like that. All the
calibrations are done by adders and multipliers inside the FPGA, so
the uP just plucks the cal factors out of eeprom and loads them into
the fpga, which saves a lot of time. Whenever my trusty old 68332 gets
too busy, Rob takes a function over from me and does it in the Xilinx.

The T344 is $3960 with power supply, a couple of cables, and ethernet.
T346 is $4800. Pricing is the least scientific thing we do.

We really enjoyed doing this one. I hope somebody buys some.

Well, I'll certainly buy one. It'll be very useful. I'll contact
you
by email to setup the Harvard vendor database stuff.
 
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