RS485 Multidrop capability

[kayjay]

Does AdvancedHMI have RS485 multidrop cabability so we don't have to have 4 USB to RS485 adapters on the PC?

[Archie]

Yes. The multidrop has been tested with both a single USB to RS485 adapter and also with the AdvancedHMI panel PCs using the RS485 port. You just add a separate driver instance for each device.

[kayjay]

Thanks, KJ

[kayjay]

But it sounds like it's not that easy when it's a raw serial port with no protocol like you mention below.

I wouldn't think it would be that hard though when we just need to send out a query commands and then read their reply/return from the several serial devices over the Multi-drop and display it in a in a Digital Panel Meter format or am I dreaming? Nothing's easy...

The SerialPort is a raw serial port and not a communication driver for AdvancedHMI controls. The drivers need to work off some sort of protocol that is address based. If it just received raw byte data, it would have no idea of how to display it and which controls to send it to.

To send and receive raw bytes, you would be more into .NET programming and not AdvancedHMI development. This may give you some idea about it:

https://tiktakx.wordpress.com/2010/11/21/serial-port-interfacing-with-vb-net-2010/

[Archie]

Your devices has to support some kind of protocol in order to know which byte indicates the target node. If the device does not support Modbus, then it will be necessary to implement a special driver for your device's protocol in order to integrate it into the AdvancedHMI ecosystem.