Problems

This page describes some problems related to S4ACS and the EMCCD cameras used in SPARC4.

Incompatibility between the SDK version and the EMCCD cameras

On May 5, an issue was identified in which flat-field images acquired by the four SPARC4 cameras reached a saturation limit of approximately 5,000 ADU, whereas the expected limit should have been around 60,000 ADU. This behavior occurred without any error being reported by the devices, making the diagnosis considerably more challenging.

During the investigation, I determined that the problem was related to an incompatibility between the cameras and version 2.104.30158.0 of the SDK provided by the manufacturer. This library was used in version v1.56.1 of the S4ACS software, which was deployed during the nights of May 4 and 5. The first night was dedicated to engineering activities.

The issue was resolved by downgrading the SDK to version 2.104.30000.0, which had been used previously and did not exhibit this behavior.

After reviewing the manufacturer's release notes, I could not find any explicit indication that SDK versions newer than 2.104.30000.0 would be incompatible with iXon Ultra 888 cameras manufactured in 2016, suggesting that the Oxford Instrument company is unaware about this behavior.