Emerson ROC 800 flow computer question...

[timothy585]

Anyone happen to be familiar with ROC 800 flow computer hardware? I'm new to the ROCLINK 800 programming software and I have a quick question.

I'm working on some small land LACT packages and I want to simulate the oil tank level so I can test the LACT's start-stop sequencing. I prefer not to wait an hour for the tank to draw down enough to go through a real cycle.

I'm sure there is a way to force the softpoint tank level value that is coming in via MODBUS from a TotalFlow. I just can't seem to find a way to overwrite the live value temporarily for testing purposes. It must be in the ROCLINK 800 software somewhere...I just cant find it.

Any input is appreciated.

Thanks.

 

[drbitboy]

Without knowing a lot about Emerson ROC specifically, I can think of a few ways to do this, but it would be useful to have some more information:

• Do you want to do this on a live system with a physical TotalFlow device providing data from a physical tank?
  • No my problem, but I would hope you have considered the safety aspects of overwriting that value, and if it's not a trivial issue then asked at least one other person to do the same
• Is the TotalFlow device a Modbus master or slave?
• Is this Modbus TCP or Modbus RTU?
  • Can you disconnnect the Modbus connection to the TotalFlow device
• Constraints:
  • How free a hand do you have with the ROC 800 program?
  • Do you have experience and/or confidence in modifying an ROC 800 program?
  • Do you want to do this without changing any code in the ROC?
    • Or can a minimal change be made?
    • Do you have a link to a programming manual?
    • Do you have the Emerson ROC programming software connected to the ROC 800 device? If yes,
    • Can you monitor live values in near-real time?
    • Does the programming software have a "Force" feature?
  • Will this test be part of a an ongoing maintenance schedule, or is it a one-time event (e.g. commissioning)?
  • Do you have a spare ROC 800 that could load the program in the operational ROC 800?

That's just a start. The answer may be simple, or it may be complex.