further explaination needed if possible

Discussion in 'General Electronics Chat' started by vijaybala85, Jun 24, 2010.

  1. vijaybala85

    Thread Starter Member

    Jan 7, 2010
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    Hi Guys,

    How do I interpret this statement?
    "Serial two wire protocol with 1MHz serial clock" or "Serial digital communication interface with 1MHz clock"

    I am trying to figure out whether it is RS232 standard or some other protocol for transmission. We are trying to make this transmission wireless, so looking at wireless RF modules that can replace the wire. But. this is all the info I get from the manual. I am trying to reverse engineer this product specs. Any help will be greatly appreciated. And also, some explanation on the 1MhZ clock concept helps. Thanks!

    Please let me know if you need more info.

    V:)
     
  2. sceadwian

    New Member

    Jun 1, 2009
    499
    37
    It's more than likley not RS232C standard, that requires -12 to +12 voltage swings for the high and low values (inverted)
    If it's a 1mhz clock it's not going to be RS232C compliant either, it's baud rates don't go that high Id on't believe, more details on the specific devices/modules you're talking about would be helpful as the information you've provided so far doesn't really explain much.
     
  3. retched

    AAC Fanatic!

    Dec 5, 2009
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  4. c_omalley2002

    Member

    Mar 18, 2010
    31
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    It's probably not rs232. That usually requires at least 3 wires (Tx,Rx, and Gnd). If I remember correctly rs485 is 2 wire communications... But I'm not sure about the clock signal...It may be proprietary. It's been a while since I've dealt with serial communications. Exactly what are you looking at?
     
    Last edited: Jun 25, 2010
  5. coldpenguin

    Active Member

    Apr 18, 2010
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    I wouldn't necessarily discount it on that fact alone, a lot of people don't count the ground wire (for example, Dallas' 1-Wire protocol uses 1 wire plus ground in parasitic mode, or two wires plus ground in power mode).
     
  6. vijaybala85

    Thread Starter Member

    Jan 7, 2010
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    Thank you all so much for replying. :)

    The product is definitely proprietary. It is a GE ECG CAM-14 acquisition module. The signals are digitized and sent to a computer serially. The protocol; That's what I am trying to figure.

    V
     
  7. c_omalley2002

    Member

    Mar 18, 2010
    31
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    I suppose you are correct. Will edit previous post. Thanks. :)
    My apologies. Apparently, alcohol has negative effects on the brain.:(

    Forgive me. I haven't dealt with serial protocols in years.

    I did a quick wikipedia search just now and found this:

    "A minimal "3-wire" RS-232 connection consisting only of transmit data, receive data, and ground, is commonly used when the full facilities of RS-232 are not required. Even a two-wire connection (data and ground) can be used if the data flow is one way (for example, a digital postal scale that periodically sends a weight reading, or a GPS receiver that periodically sends position, if no configuration via RS-232 is necessary). When only hardware flow control is required in addition to two-way data, the RTS and CTS lines are added in a 5-wire version."


    To have a clock signal, I would think that 1 wire would be your clock and 1 would be your Signal.....

    To vijaybala85: What type of computer? Like a PC?
     
  8. Wendy

    Moderator

    Mar 24, 2008
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    2,536
    How about USB? Sounds kinda close from what I'm reading, and a lot more common nowdays.
     
  9. coldpenguin

    Active Member

    Apr 18, 2010
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    I recently bought a Logic analyser, it can automatically decode several different protocols (i2c for example is clocked, and many people do not call it i2c because of licensing issues)
    You select the protocol you think it might be seeing, and the software tells you what it thinks it is saying.
    Could be worth a shot. Probably ~$140 for you to find out though (although I think the one which I got had a money back guarantee)
     
  10. vijaybala85

    Thread Starter Member

    Jan 7, 2010
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    @c_omalley2002 The signal is sent to a CAM-USB interface with the computer. The pictures can be found on CardioSoft service manual. The software on the computer displays the ECG.

    @coldpenguin I will look into it. Maybe our lab may already have one.

    PLease refer attachment for info on module. Thanks!

    V
     
  11. c_omalley2002

    Member

    Mar 18, 2010
    31
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