Welcome to the TRNSYS Users Forum.
The forum is a place where people can interact and have discussions about different topics involving the use of the TRNSYS software package. Here you can post topics for discussion or questions on using TRNSYS and get advice from other users or TRNSYS experts. This forum is not intended for detailed technical support. Users should contact their distributor’s hotline for such assistance.
Some tips for success on using the forum:
- Follow the Forum Rules posted in Forum Administration.
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My simulation runs fine, but when I click on the ‘Results, warnings, and errors’ icon, I see several notices. Even running one of the examples that comes with TRNSYS, I get a lot of notices, and a few warnings. Why am I getting notices and warnings in my simulations?
There are three levels of messages TRNSYS prints to the log file: notices, warnings, and errors.
‘Notices’ are not a problem. Every project has notices for how TRNSYS is compiled, where the TRNSYS executable (.exe) and main TRNSYS dynamic link library (.dll) were found, and which libraries were used to load components. If your UserLib folder contains TESS libraries or other user Types, you’ll get notices for each of these as well, even if the project doesn’t use them (in which case it will just say “<Library name.dll> was found, but did not contain any components from the input file.”) Types like Type 56 can also write notices. The number of notices really doesn’t matter. They only come into play if you are debugging and need to confirm which copy of TRNSYS is running and which libraries it’s using; some users have multiple TRNSYS copies, and some Types are copied in multiple libraries. Otherwise, notices can be ignored.
‘Warnings’ and ‘errors’ deserve more attention. ‘Errors’ will stop a simulation, and they have to be addressed. Contact your distributor if you need help fixing errors in your simulation. ‘Warnings’ may or may not be a problem, depending on how often they occur and how your simulation is set up. For example, a controller Type may warn that it was “stuck”, meaning it oscillated between ON and OFF too many times in a timestep and was forced to stick to one state or the other. Any sticking deserves a closer look, but if it only happens, say, <<1% of the timesteps in a simulation, it may not impact the results enough to warrant much further tuning. On the other hand, a controller that sticks >10% of the time almost certainly means the project needs more capacitance, a smaller timestep, or other troubleshooting. Another good example is the pump/fan mass balance warning on Types that set flow rate. In a closed loop application, the flow rate returning to the pump/fan should always equal the flow rate it sets for the loop, and any mass balance failure probably means there’s a missing flow rate connection, an erroneous flow rate connection (such as to/from the wrong port on a manifold or plenum), or a conflicting control signal somewhere in the loop. However, if the Type is used in an open flow application (such as a fan drawing outside air, or a pump from a large pond), and there is no return flow connected, there could be a mass balance warning on every timestep, and it could be safely ignored.
