This year we've struggled with vacuum controls unreliability (e.g., spurious interlock triggers) caused by decaying hardware. Here are details of the vacuum refurbishment plan I described on the 40m call this week.
☑ Refurbish TP2 and TP3 dry pumps. Completed [ELOG 15417].
☑ Automated notifications of interlock-trigger events. Email to 40m list and a new interlock flag channel. Completed [ELOG 15424].
☐ Replace failing UPS.
☐ Remove interlock dependencies on TP2/TP3 serial readbacks. Due to persistent glitching [ELOG 15140, ELOG 15392].
Unlike TP2 and TP3, the TP1 readbacks are real analog signals routed to Acromags. As these have caused us no issues at all, the plan is to eliminate dependence on the TP2/3 digital readbacks in favor of the analog controller outputs. All the digital readback channels will continue to exist, but the interlock system will no longer depend on them. This will require adding 2 new sinking BI channels each for TP2 and TP3 (for a total of 4 new channels). We have 8 open Acromag XT1111 channels in the c1vac system [ELOG 14493], so the new channels can be accommodated. The below table summarizes the proposed changes.