USB 6501 to read & write on ADT7461. How to program it? Emulate a C programming

[Nicki]

Hello!  The bit sequence  look like this:



1-     from A7 -à R/W   is THE DEVICE ADDRESS + R/W

(we have address plus a bit for write or write to the register that the  address is represented in  D7 -à D0)

2-     Each sequence is ACK acknowledged by the ADT(the element to write or read from) a Read bit  = 1/ Write bit = 0

============================================================

3-     Microprocessor  send A7 à R/W;//master

4-     ADT acknowledge by sending 0;//slave

5-     Microprocessor send the address of the register to R/Wwith;(1/0) then come the array reading.

 

 

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*My question is how to do a reading and writing to register that have their addresses *as sequenced?

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There is a Maxim device that has 15 bit and need to be read; totally different from the above ADT.

There is a start bit , and then a dummy bit and data and stop bit.

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*How  data coming out the port?*************************

I have atached the Max clock and data diagram

 


MAX6675.pdf:
http://forums.ni.com/attachments/ni/70/6621/1/MAX6675.pdf

[Raajit L]

Hello,What is the programming enviroment that you are using?&nbsp; Could you tell me a little bit more about your application?&nbsp; For example, are you going to be using DAQmx functions to read and write to your device? Is the USB-6501 the only hardware that you are using in this application? How many channels are you going to be using on the USB-6501 and what are the inputs to each of those channels?The USB-6501 digital channels will just recognize signals as high or low, and the same holds true for writing on the channels as well.&nbsp; The device is capable of TTL logic.&nbsp; This means that how the data is output on a port of the 6501 can be customized by you in the programming environment.&nbsp; You can send a high or a low on every line of the port.&nbsp; Something, that you should keep in mind is specifications of the USB-6501 such as pulse width, source frequency and other parameters and how these apply to your application.&nbsp; You can find more information about the specifications of the USB-6501 <a href="http://sine.ni.com/nips/cds/view/p/lang/en/nid/201630" target="_blank">here</a>. Regards,<a href="../view_profile?user.id=83711" target="top" class="auth_text" style="font-weight: bold;"> </a>
Message Edited by Raajit L on 04-04-2007 01:05 PM

[nICKI]

Briefly here is Sequenses*************************Matser USB6501)initiate the communication by sending
&nbsp;------------&gt;Start bit(SDA =0) + Device address(0x4c) + 0/1(w/r)Device acknoledge by sening
&nbsp;-----------&gt; Ack = SDA = 0(all total = 9bits);Master send the address wher to read/write
&nbsp;-------&gt;8bitsDevice Ack by ringing down the SDA =0;Device will accept DATA or out put it ;I have all the sequences in C but I have problem to put them in Graphical LabView
&nbsp;

Definitely I will use DAQmx to run the 12 channels all managed by USB6501:each channel has an ADT7461 connected to it and all doing the same.
ADT------------&gt;USB6501----------------&gt;PC
-initiate communication by sending start bit SDA = 0;
-initialize the registers in ADT7461 as follow;(hand shakings&nbsp;+ messages) as the following program will explicite.
If you need more explaination I willing&nbsp;to do it.&nbsp;
&nbsp;
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[nICKI]

Raajit ,
&nbsp;
I thank you for your time and effort&nbsp; you put into this problem to get a solution.
I tried to upload the program that I wrote from C but the limit of the characters to be posted couldn' allow me.
I am aking if I can postlittle by little this way you can see what is my idea.
Let me know I constantly on the web.
&nbsp;
nICKI