Serial Communication with Xenta Units (511, 527, 911, 913):

Issue

Serial Communication with Xenta Units (511, 527, 911, 913):

Product Line

TAC Vista

Environment

  • Xenta Servers
  • Xenta 511, 527, 701, 711, 721, 731, 913

Cause

Incorrect cables can cause improper ground references between the PC and the Xenta unit, which will disable serial communication.

Resolution

The Xenta units that utilize a web interface all have a certain amount of setup that is done with a direct serial connection via HyperTerminal. This communication however can be problematic at times due to grounding between the Xenta unit and the computer. If both devices do not share a common earth ground reference, then communication will not occur at all. There will be no indication that either side is receiving the transmissions from other device. This is most commonly encountered when using the incorrect cable since the proper cable provides a conductor for ground and thus a common ground reference.

An OP panel cable is not the proper cable to use in such a situation. Instead you should be using the cables found in the TAC Xenta programming Serial Kit. If you are using a cable made by someone other then TAC the most likely cause is your cable having the improper or insufficient connections.

When stuck in a situation where the proper cable is not available and working with a laptop computer we recommend that you plug the computer’s power supply in preferably to the same power supply as the controller to try to establish the common earth ground. Any other attempts to stabilize the differing grounds will be at your own risk.