Why are LED, F-Key and Buzzer variables not supported in Topology Bus Terminals?

FAQ #100361

 

Symptom
FKeys (PCD7.D79x, PCD7.D231, PCD7.D232), LEDs (PCD7.D232), Buzzer (PCD7.D23x) and the popup of the alarm buffer (all displays) are not supported in RS 485 Bus Terminals Topology!

Reason
Because the RS485 Bus Terminal Topology does use a specific protocol which does not support special telegrams such as the one used for accessing the LEDs or for evaluating the F-Keys, these features are not supported on RS485 networks. In case the LEDs, the F-Keys or the buzzer is required, please connect the display with RS232 to the PCD.