GPIB-Connected Devices: Troubleshooting

Communication Error

A communication error may occur when you install a driver in the Server Configuration program. Possible reasons are:

• The instrument is either turned off or disconnected from the mains.

• An invalid address has been assigned to the instrument.

• Only for the Waters Separation Modules (2690(D)/2695(D) or 2790/2795): The Controlled by Millennium 32 option has not been enabled on the module. (The Administrator Help section provides more information; refer to Hardware Installation  Waters Alliance 2690(D)/2695(D) HPLC Modules: Installation, Device Settings section.)

• The instrument is not yet completely initialized.

• There are problems with the cable.

• The instruments are not connected in series. One or more instruments are connected in a star structure.

• One or more of the instruments are turned off.

• There are more than 20 devices connected.

• The cable length between two instruments exceeds 4 meters.

• The average cable length between the separate instruments connected to a bus exceeds 2 meters.

Remedy the situation, and then reinstall the driver in the Chromeleon Server Configuration.

Problems with Cables

If problems occur with a cable, follow the steps below:

1. Turn the instruments off.

2. Perform the following steps in succession for the individual instruments:

• Connect only one instrument to the PC.

• Make sure that the GPIB address for the connected instrument is correct.

• Wait until the instrument has completely initialized.

• Try to connect the instrument from a Chromeleon panel.

3. If you cannot connect to the instrument from Chromeleon, the reason is mainly that the cable is defective. Turn off the instrument and replace the cable.

Also, refer to  Waters Instruments: Troubleshooting.