Specifications

Updating Project Versions Appendix A: Troubleshooting
112 VisiLogic: Getting Started
Updating Project Versions
Opening a project created in a previous version of VisiLogic enables you to
update the project. Please note the following:
If you open the project with the new version, but do not save it before
closing it, no changes are made to your project.
VisiLogic automatically creates a backup file of the project you are
updating. This file is located in the project directory. This backup file does
not have the .vlp (VisiLogic) file extension. In order to open the backup,
you must change the file extension to .vlp.
You can also save the original file by opening the project, and then
performing File>Save As, assigning the new file a different name.
In order to deliver a high level of service, Unitronics issues software
service releases that fix known issues. However, in some cases, users
develop workarounds for these issues. If you have developed a
workaround in your project, and then update to a VisiLogic/OS version
that fixes the original issue, your workaround may not function as you
expect.
Known Issues: Version Incompatibility
Certain versions have changes that may impact on the running of an
existing application if you update the OS in the PLC.
V120-12-xxx is no longer supported, in released version VisiLogic
4.7.4, OS 470 (06), and later.
Previous to Version
After Version
Version 4.00, Build 00
Call Display function
Any contact could be used to
trigger a Call Display function to
call and load a display.
A positive transition contact , or the
rising edge of a contact such as SB 7
100mS Pulse is required to trigger a
Call Display function.
PID function
VisiLogic versions older than 4.00 contained a PID function. This function
has
been replaced by the PID FB, which offers Auto-tune plus other advanced
operations.
If you open a project which implemented PID using the older PID, you will
receive the following error message:
"This project contains X number of outdated PID loops. Using
outdated PID limits you to 4 PID loops. For more information,
please click on the Help button below."
Although older projects will function, it is recommended that you update
these projects, replacing the PID function with the PID FB. Please note that