Bill Linne

Robert: The data can come from many places. It really depends upon what else is connected to the PLC. In my system, we use radio telemetry to gather data from many distant sites. Each site has a block of memory to which it writes. Then that data is displayed on the HMI. (Obviously, the same is true for the HMI to control the distant stations.) Also, other PLC's around the plant can MSG (message) data to each other, so certain areas of memory are reserved for that activity. They are interconnected via DH+ and Ethernet. Analog input modules will also write into whichever area they are configured to do so. Many possibilites. You'll need to track it down. Bill

Hi: I give up, what is TPM? Thanks, Bill

Hi: Not to pick nits, but you did use resistors (plural). To the best of my knowledge, there should never be more than one resistor on any blue hose circuit (DH+ or Remote I/O). Try removing the resistor nearest the PLC. I'd also check the configuration of all your communication ports on the PLC, particularly the RIO port. Bill

Gents: I did misread the request for address, and furnished the control address for the BTW, not the data address. But I investigated the data address too, and found only one word of the the ten words to have a value in it. And that value did not match any of the valuse in the MIN/Max fields of the module. I may post a shortened version of the file tomorrow. I really appreciate the help, and I know that we'll get to the bottom of it eventually. Thanks again, Bill

Where does the data "live" for these modules? When viewing the data table (in module setup), you are presented with the present data value (I know where that lives!) but you can insert the Raw Min and Raw Max values for each channel, too. Where do those values live? The reason I ask is because in one of my modules, the Raw Min and Raw Max values are not static - they are frequently changing. Which means, I think, that the buffers they are in are being overwritten by something else. Without knowing where the values are, I don't know how to isolate the offending instruction that is overwriting them. Any ideas? p.s. I sure hope that this is not so simple that I look like a dummy . . .

Okay, the BTW is at N14:0 and the BTR for the same module is at N14:10. The next module uses N14:20 & 30, respectively. When I view the N14 registers, only the first five words of each are other than zero. All words x5 thru x9 (05, 15, 25, etc) are zeros. Did I misunderstand something?

OkiePC (and others): The reply immediately above is mine. I forgot to log in before posting it. Sorry.