Panel Meter Communication Library FAQs

What are the Optional Timing Parameters on Initialize.VI for?

In modbus communications via the RS-485 bus, there are required delays between messages on the bus which are based on the serial baud rate. Sometimes it is desirable to insert additional delays to account for noise, slow settling, slow device response or other factors. The Optional Timing Parameters also include the ability to specify how long to wait for a message before timing out and how many times to automatically retry if there is an error. Under normal circumstances, the default parameters are adequate; however, if you are experiencing intermittent communications in a noisy environment, you can try adjusting these parameters.

The installation seemed to go ok, but I can’t find the libraries in LabVIEW?

If LabVIEW was open when you ran the install program, have you closed and re-opened LabVIEW as instructed by the installation program? The libraries can be accessed by right-clicking the block diagram and looking under the User Libraries pallette or by looking under the LabVIEW Help menu.

Also, the installation program places the libraries in the most current version of LabVIEW installed on the computer. Check to make sure you have opened this version of LabVIEW.

Why are multiple meters supported on RS-485 serial but only one meter on USB or RS-232 serial?

An RS-485 serial bus can address up to 31 devices, whereas RS-232 is only capable of point to point, single device communication. The CUB5 USB option emulates an RS-232 port.

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