As shown, I have linked to a specific PLC tag and selected “present value ID#85” which implies HMI will read the Binary Value.
I dont understand how to define whether it is read or write. In this case I want the HMI to write to the PLC, so do I need to select a different BACnet property for writing? Which? Event Enable?
The memory address associated with the toggle switch allows both reading from and writing to that address through the toggle switch. If you want separate memory addresses for read and write within the toggle switch, please select the “Read/Write use different addresses” box. Each object within EB Pro lets you know whether it is a read, write, or read/write object in the General tab.
As for the PLC, please ensure the settings allow for reading values from the HMI
When I set up a toggle switch linked to the PLC binary value I want to write-to, it seems counter-intuitive to select property #85 Present value if I want to write not read.
Should I select a different BACnet property or service?
I’m not all that familiar with BACnet, but in the Modbus world there are different function codes for write (05) and read (01). I would expect that BACnet would also require different codes to perform a write compared to a read?
Thank you for confirming the BACnet property. selection.
I now have this working properly.
Among other things, I had set the Toggle Switch Attribute to “Set ON” instead of “Toggle”.
I dont understand what Set-ON and Set-OFF are for - since that locks the switch in one position??
The set on and set off feature, it’s common to share the same memory address across multiple objects, for example, a Toggle on the main screen and a separate “Off/Reset” somewhere else, or have the PLC auto-reset the bit after it sees a “Set ON” command. If you ever need separate read vs write points, you can also turn on “Read/Write use different addresses.”
