ShaunR

Well. The difference may at first glance seem semantics. But it is fundamentally important. Whilst "Bi-directional" literally means "2-way", Full duplex means "2-ways simultaneously"!. If you think of the difference between a walkie talkie and a telephone. One you cannot hear the person at the same time as you are speaking, the other you can. But they are both bi-directional. Its much harder having an arguement on a walkie talkie than a phone...lol. I wouldn't agree that RS485 implies 4 wires. (RS422 yes but not RS485). Almost all modern industrial PC's come with at least 1 COM port that is configurable to RS232, RS422 and RS485. Only when configured to RS422 does it use 4 wires. RS485 they use only 2. The good thing is though, that RS485 works with RS422 but not the other way round So if you set the PC to RS422 you get true full duplex operation and can talk to RS485 devices. The penalty is that the bus cannot support as many devices. I think we will have to wait for USB 3.0 for true full duplex USB

You also need to install the Vision Development Toolkit. And the Motion Control Toolkit which are installed separately.

NI 9485 x 2

I have my moments. As few and far between as they may be though Ah. Thought you wanted to definitively know. Just for reference. It will also show as maximized.

Not sure if there is a better way. But if you try to load it into a sub-panel and it is already in one, you will get Error 1145 Possible Reason(s) Labview: Cannot open VI because it is already in a subpanel control. If its not in memory, it will succeed, and if its already running but not in a sub panel you get Error 1144 LAbview: Cannot insert VI in subpanel because VI is already open.

OK. So your convinced you need a digital OP. (If you are insistent on NI products compatible with your chassis, I would have chosen the NI 9485 purely because it is 1/2 the price of a digital card but still 4x the price of other alternatives). From your image I can guess that your sensor port is in fact a constantcurrent source. This makes sense to me as changes in resistance willyield a change in voltage as the load increases/decreases. (This is whyyour analogue output idea won't work). If you think of a current sinking digital output as a transistor switchto ground. Then (relating that to your diagram) each Digitaloutput would be connected to the other side of the resistor. i.e between the resistor and common. If you are using it in this manner, it is important that you DO NOT connect the External supply to the Digital modules External Power Supply Terminal. This is because internally, each "transistor" is connected to the External supply pin via a resistor. You would in effect be putting this in parallel with all of your other resistors you are using. You also have to remember that it is "inverted logic". i.e setting the output to "1" grounds the device, but this can be changed in the NI configuration if it hurts your head. Get the NI 9485 unless you are looking for fast IO and it will directly replace your switches and half the price...No brainer!

I think you are missing the point. The image is an "example" of a counter. Not a solution to your project (that would be too easy ). Look at what it does and how it works and apply it to your current "real" example. Your dependency on the "i" iterator will cause you problems since it increments every loop execution. Your dependents need to use a counter (oooh...like the example ) that can be started and stopped regardless of how many times the loop executes.

Like I said. Twice as long (as 1/2 its length).

Not surprised. Or ya could use one of these or something similar. Google for em. USB Relay Board

You need "current sinking" digital outputs, then you can switch the resistors in direct without relays. The 9172is a chassis. what modules do you have currently? You could also use the parallel port to switch some relays (be carefull about current though). Or a non NI rs232 digital board (about $90).

Amen...lol. Just look at the internet toolkit and the Vision stuff

Twice as long

First you will need to allow the time-out case to execute by wiring a value (say 100ms) to the blue icon in the top left hand corner. You will then have to use the state of the "Running" boolean to decide whether to increment the counter or not. You can use 2 shift rgisters (one for the state and once for the count). This is thesort of thing you will want to use for the counter.

NI also do PCIe cards.

Sounds good to me. I would suggest darlingtons on the output if current is required.

I agree. It has some unintuitive behaviour. It also has a couple of bugs. There's also MGI which is based on the WinInet.

Many moons ago, I had a vi that was basically a wrapper around the write to spreadsheet.vi. It was for a data logger, and since the customer didn't really know what data he wanted saved (and kept changing his mind); I wrote a fairly simple vi that read the header (first row) and compared it to the current header to be saved. It would look at the header and, if a column was different, would insert a new column in the existing file (i.e upgrade it). If the headers were the same, it would just append the data. Old data therefore had no entry in this new column, but the new data would, but both the old and new would still be in-line with the headers. One caveat with this was that you could not rename headers, but that wasn't a problem in my case.

Just for simplicity, I would suggest a TCPIP packet thats sent when your global changes. 2 seconds to add and has the advantage that you don't necessarily need labview on the remote machine (a C++, Delphi, VB app for instance). I prefer TCPIP over UDP since it is far more reliable, although it is not connectionless (i.e you need a target IP unlike UDP broadcast). Once you start down this route, you will quickly find that you want more and more information and it is very scalable and easy to implement

FWIW???? The Vista x32 installation I tried above was on a Acer Core Duo Laptop. It's probably got more to do with multiple installations. I always have problems with activation since I have to do them manually and (for me) its not worth the aggro having multiple installations.

I think you are still confusing Bi-directional with Full Duplex. Take for example the Micro-Epsilon Micrometers and 2D/3D Profilers (just an example, since I used them recently). They can operate by "streaming" data back to the Master (important for high speed acquisition). If this were to be used in a half-duplex manner, then once switched into this mode, you would not be able to control the device since the device is continuously transmitting. However, with full duplex you can. In another scenario, we have 1MBPs full duplex RS485 digital IO boards. The protocol is a command-response type which is appropriate for half-duplex operation since the devices don't start to transmit until a full message has been received. However, since we have upto 10 of these on a bus, most of the time, the RX line is saturated with messages. We can decide to ignore RX messages if they are a bit stale (since the devices must use hold-off and wait untill the line becomes free due to another device transmitting). But we cannot allow the device not to operate on commands immediately via the TX line. Devices such as these are quite common. And "True" full duplex devices actually start constructing the response on the RX line before the entire TX message has been received.

Don't know how MAX does it, but all the NI product versions are available in the regsitry under HKEY_LOCAL_MACHINE\Software\National Instruments\XXX\CurrentVersion where XXX is the package.

Well. Your drive also seems resistant to WMI as well The pervious DLL used 3 methods, the final one being querying the WMI database. Hmmm. Digging deeper........

Whats wrong with the "Write To Spreadsheet File" in the file functions palette? Simple 2D array where the first row is the header.

Try using the "To Variant" function then comparing.

I've just installed LV2009 on Vista Ultimate x32 to see if I get the same problems. I didn't and it is working fine. Are you sure you are installing the 32 bit version of LV 2009 and not the 64 bit version? I didn't try the x64 to see if the installer complains.