I am trying to control the parallel port of my PC using TwinCAT software from Beckhoff. I get the message " Unable to access port 801". My PC uses a XP Professional OS. My guess is that the PC settings forbid any attempt to access the port directly.

How to change the settings to make the program access the parallel port?. Port id is 378h.

 

Are you using a Beckhoff PC?

The 801 message is due to trying to log in from PLC Control and the TwinCAT System Service being still in config mode and not in the run mode. You must configure the port manually in the System Manager, generate mappings, check configration, activate registration and put system in run mode. Then you will be able to go online from PLC Control. Please contact 1-877-TwinCAT for further support.

 

Your TwinCAT System is not in run mode. Port 801 is actually referencing the PLC port of the RT-System.

Here is a video that shows setting up a system with Parallel port communications.

Corey

 

Hi,

Port 801 in case of TwinCAT is an ads port, which is used to communicate with a PLC runtime. It looks to me like you tried to go online while your TwinCAT system is in config mode.

Try the following: TwinCAT tray icon right click -> System -> Start

If it's not your case, please elaborate when you get the message.

Regards,

Jacek Dobrowolski