DigitalFarmBoy

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Posts posted by DigitalFarmBoy

  1. Posted · Edited by DigitalFarmBoy
    Fixed accidental Italics

    I am aware of using the % symbol for addressing with a single variable, but wasn't sure how the program handled that when used for an array. In the example above, I am assuming that the PLC will assign testArray[0] to location %W0, testArray[1] to %W1 and so on, is that correct? This was my initial assumption but...

    I built a quick sample program where I created a single UINT and an array of UINTs and mapped them both to fixed memory:

    5e1ca44590961_Annotation2020-01-13110231

    When I run the simple program (sets Test := i in a FOR loop through 16 and sets ROS_OP_MODE to 1), I looked at the variable watch, and while it shows my AT specification for the single UINT (%E0_0), it doesn't show any AT specification for the elements of the array. This is why I wasn't sure if I was defining the array AT specification correctly.

    5e1ca4463f7f9_Annotation2020-01-13110323

    I don't have hardware on hand currently, so I can't verify if the simulator is not showing this correctly or if the array isn't actually mapped to the memory as expected. Either way, I would like to be sure before I spend a bunch of time programming and then find out that it does or doesn't work.

    1 hour ago, Michael Walsh said:

    Why do you need to assign an address to the variable?  This is only necessary if you have a very specific need to do so.  

    I'm working with a couple HMIs that talk to the PLC using the FINS Ethernet protocol, so I need to map variables used by the HMI to specific memory locations in order to access them remotely.

  2. Posted

    I'm having trouble specifying a memory location using the AT specification for an array in the Global Variable tab. I've tried a number of different ways to do so, and searched around online but haven't been able to find anything about how to do this. All I have to go from is the rather cryptic "AT specifications are specified separately for each variable. Set them for all elements and members
    of array, structure, and union variables.    " from page 6-62 of the Software User's Manual (W501).

    That seems to imply that it can be done somehow, but I am not sure how. Right now I have created array elements as independent variables, and then use a FOR loop with a CASE statement to put the proper variable into the array for use later in the program. This doesn't seem particularly efficient, and I have to imagine there is a better way.

    Any advice on this is greatly appreciated. Thanks!