Internet PLC Forum

I'd like to call PIDCompute for 7 different channels in a for-next loop, something like this:

for I = 1 to 7
     E= ... 'Determine the error
     T=PIDCompute(I,E)
next 'I

I get an error each time I try to compile.  When I take the PIDCompute out of the loop and call the function with a channel number (rather than a variable, I), I get no error.  for example:

T=PIDCompute(1,E)
works OK.

I'd like to call the function in a loop with the channel indexed.  Is that not permitted?
Thanks!

I've been searching for guidelines on setting the cjc offset for an i-7018.  I know how to set the offset--I just don't know how best to determine what offset to use.  This doesn't seem to be part of the calibration procedure for the i-7018.  The best I've got so far is to adjust the cjc offset till the thermocouple readings match a (hand-held) reference temperature.  Is there a better approach?

Could you tell me how I can exchange data between a program running on a PC and the PLC via Xserver?  

What I'd like to do is periodically send data over the internet from the PLC to a program running on a remote PC, and then have that program send data (updated parameters, say) back to the PLC.

I found info (in the XServer instructions) for writing and reading to a file on a remote PC, but these are PLC-initiated instructions.  Can a remote program request information from the PLC?  I assume this is what the ExcelLink code does.  How do you do this?  What are the available commands and syntax?
Thanks in advance.