Troubleshooting - Poor EMI grounding

Applies to	All output devices that have SCSI data communication with the Workstation.

Machines affected	All

Error number	n/a

Component	SCSI cable terminations.

Problem	The basic problem has to do with poor high frequency termination of the shields of SCSI and serial cables to the imaging device.

Symptoms	Random SCSI errors Workstation communication errors Erratic behavior of the keyboard (keystrokes that were not struck) and possible data corruption as shown on the image as artifacts

Causes and Solutions	The communication cabling from the Creo workstation to the output device is very critical to the performance of the system. The SCSI cable is a braid shielded 68-conductor cable that transfers imaging data from the workstation to the output device. The shield protects the data from noisy environments by blocking any radio frequency disturbances from corrupting the data. To ensure performance the shield MUST be properly terminated to chassis at the workstation as well as the output device. The serial communication cables for the workstation as well as the diagnostics cable follow the same process. It is essential that these cables are the cables specified by Creo as lower quality cables may not have the shielding effectiveness or proper termination required. If a customer system exhibits these errors check the following: Use an ohm meter to measure continuity of the connectors to chassis ground at the bulkhead of the recorder (scrape away paint if required to make continuity, should be less than 1 ohm). Make sure the cables are the correct cables as specified by Creo. Check the serial cable connections and the terminations of the shields (make sure the 9-pin D-sub connectors are screwed to the bulkhead). Trace the cables from the recorder to the workstation and move them away from any high noise source such as inductive motor, switch contactor, vacuum pump or motor driver etc. All Creo recorders are certified to comply with the emission standards and the immunity standards. However, individual machines may be more sensitive to RF fields and individual environments may be more severe than what we tested for.

Causes and
Solutions

The communication cabling from the Creo workstation to the output device is very critical to the performance of the system. The SCSI cable is a braid shielded 68-conductor cable that transfers imaging data from the workstation to the output device. The shield protects the data from noisy environments by blocking any radio frequency disturbances from corrupting the data. To ensure performance the shield MUST be properly terminated to chassis at the workstation as well as the output device. The serial communication cables for the workstation as well as the diagnostics cable follow the same process. It is essential that these cables are the cables specified by Creo as lower quality cables may not have the shielding effectiveness or proper termination required.

If a customer system exhibits these errors check the following:

Use an ohm meter to measure continuity of the connectors to chassis ground at the bulkhead of the recorder (scrape away paint if required to make continuity, should be less than 1 ohm).
Make sure the cables are the correct cables as specified by Creo.
Check the serial cable connections and the terminations of the shields (make sure the 9-pin D-sub connectors are screwed to the bulkhead).
Trace the cables from the recorder to the workstation and move them away from any high noise source such as inductive motor, switch contactor, vacuum pump or motor driver etc.

All Creo recorders are certified to comply with the emission standards and the immunity standards. However, individual machines may be more sensitive to RF fields and individual environments may be more severe than what we tested for.

Poor EMI Grounding