Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 2
Human-Machine Interface; Communication Breakdown; Situational Awareness
ATC Issue All Types; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Weather / Turbulence
Air Traffic Control Separated Traffic; Air Traffic Control Issued New Clearance
Weather; Human Factors; Procedure; Airspace Structure
Aircraft X was northwest bound near ZZZZZ intersection at FL260. The sector next to me was Sector XX; in another area. They had coordinated with my previous sector controller that they would just PVD (Display Data Tag) their ZZZ arrivals to my sector and would descend into my sector airspace without a 'phone call'. The controller I relieved informed me of this temporary agreement. As I took the sector; it was fairly busy and complex with significant weather impacts to the sector and ZZZ gate swaps in effect due to weather at the arrival gates. I don't know for how long I had a PVD on the aircraft that would eventually conflict with Aircraft X; but the first time I noticed the ZZZ arrival; the datablock indicated 27;400 feet; descending to 17000 feet (likely given 'descend via' by the sector XX controller). As soon as I noticed that the ZZZ arrival was potentially descending through Aircraft X's altitude; I issued a 020 heading to avoid the ZZZ arrival. Once I was confident this would add separation between the two aircraft I returned to other tasks and aircraft. I can only assume that sector XX did not see this traffic and I don't believe I displayed Aircraft X to sector XX. I should have done that and called to reference the traffic. Again; I'm not sure how long I was aware of the ZZZ arrival.Don't allow other sectors to simply PVD as a means of coordination. Perhaps a D-Side (they may have had one) on sectors would have helped with the coordination.
Controller had a data tag of an aircraft being worked by the adjacent Controller displayed on his radar in his sector airspace. No verbal coordination had been accomplished. Normally verbal coordination in addition to the data tag display is required in this situation. The controllers agreed for this time period that verbal coordination would not be necessary. The reporter did not notice the displayed data tag in his sector in a timely manner and had to turn one of his aircraft away to achieve separation.