Error Condition: Command byte transfer error.
Description: EBUS results when certain GPIB bus errors occur during device functions. All device functions send command bytes to perform addressing and other bus management operations. Devices are expected to accept these command bytes within the time limit specified by the default configuration or the ibtmo function. EBUS results if a timeout occurred while sending these command bytes.
Possible Cause: There are no GPIB devices attached to your GPIB controller. This can be because all of your instruments are turned off, one of your instruments is in error and is asserting a handshaking line, your GPIB cable is disconnected from your board, or your GPIB cable is broken.
- Verify that all instruments are operating correctly, and that the ones you wish to communicate with are indeed powered-on.
- Disconnect all instruments and connect them one at a time to determine if one instrument is causing the problem.
- Check for loose or faulty cabling, and make sure that at least 2/3 of your instruments are powered-on (this is a requirement of the IEEE 488 specification).
- If the timeout period is too short for the driver to send command bytes, increase the timeout period.