AD 240CPU remote com problems.

Using DS4.0 we seem to be having some problems changing a timer value via remote modem conntection. I have no problems connecting or compairing the program (plc to disk), however when I try to download the changes to the PLC I'm expierencing a com error during the write phase of the download.

So the problem really could be just a lousy or noisy phone line, so my workaround is not to download the entire program, but to change the timer value (K-value) only. Problem with that is I cant find the Vmem loactaion for Timer 101. I just want to change the K-value. I presume this is in some memory location, but which one? I know the accumerator, and status bit location but where's the preset?

Thanks, Mike.

The 'K' value is the next word in the program file itself. Make sure your ladder view options is by address (not by rung) and note the address of the timer. Next go to mnemonic view and go to that address. You'll see that the 'k' value is right there after the timer definition.

I'm begining to think the communication problems may be in my office, or something with DS4.0. I tried writing to 4 remote PLCs today and NONE of them will do a complete download. I drove out to the one site today and made the necessary change, but I have to get to the bottom of this.

By the way, it seems the only way to change the preset on a timer is with the program write, or go to the jobsite.

Mike

elevmike said:

By the way, it seems the only way to change the preset on a timer is with the program write, or go to the jobsite.

Click to expand...

As far as I know, that's correct. I've been bitten by that too...

I suspect from now on you'll start using retentive V-memory for you timer preset values, Mike...

beerchug

-Eric