Re: [TRNSYS-users] Data reader: how to always read the last row of a file

Dear David，

Thank you very much for your advice.

Upon this problem, one of my colleagues also informed me a good solution. This method is to use Type 62 (TRNSYS-Excel) to make Excel as the interface between the monitoring system and TRNSYS. In this way, when the monitoring system writes new data into the Excel, the updated data can be input to TRNSYS.

About how to hold on the simulation process, our IT technicians can help us to solve this problem. Actually, the "Pacemaker" in TRNSYS can also provide the delay for the simulation, but the delay from "Pacemaker" will be a constant time instead of variables.

Kind Regards,
Sunliang Cao

Date: Fri, 15 Nov 2013 14:59:23 -0600
From: d.bradley@tess-inc.com
To: trnsys-users@cae.wisc.edu; caosunliang@msn.com
Subject: Re: [TRNSYS-users] Data reader: how to always read the last row of a file

Sinliang,
Interesting problem! I do not know of any component that can do that, unfortunately. It would seem to me that you are going to need a component as well that makes the TRNSYS simulation sit and wait until the file has been updated. Since the simulation time is set internally in the kernel this might prove to be challenging but if you do force the simulation to wait before it is allowed to progress on to the next time step then I would think that once time does progress, Type9 would just advance the file by one line and read it and that it wouldn't care if it were the end of the file or not. In any case whether you have the component that reads the last line of a file or whether Type9 will serve the purpose I think you will need to write a component that will hold on to the simulation time until the monitoring system updates the file.
Kind regards,
David

On 11/15/2013 07:42, SUNLIANG CAO wrote:

Dear all,

I have a question about the "Data Readers" in TRNSYS. Normally we use Type 9 as data readers in our simulation, which read the data file either from the first line (row) or skipping several lines (rows) from the first line (row).

However, is there any data reader in TRNSYS which can always read the data file from the "last line (row)" of the data file?

For example, certain data file is connecting to a monitoring system, and continuously generates new data rows. And we need to always use the last row of that data file for the TRNSYS simulation at each time-step.

Kind Regards,
Sunliang Cao
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