What does the message "Relay URL: Socket was closed by peer" mean?

FAQ #101676

 

Symptom
The PPOs in an S-Web Editor project are not displayed on a VGA MB Panel (PCD7.D4xxV), but instead the message "Relay URL: Socket was closed by peer" is displayed in the message window.
This message can also be displayed if an S-Bus communication is configured (between a serial port of a PCD containing a Webserver and a VGA MB Panel on port 0 or 1).

Possible reason
This message means the communication isn't working due to the fact that

• If a http connection is used:
  The server has closed the connection for some reason.
• If a Serial-S-Bus connection is used:
  The communication can not be established because the
  - cable is not correct
  - the wrong port is selected
  - the PCD does not have an S-Bus address, or there is no port assigned as S-Bus slave
  

Solution
Check the communication cable, serial port, if possible change of serial port (RS 232 -> RS 485)! If a http connection is used, please check whether the IP of the PCD is configured correctly.