看看这个:
Chase PaymentTech:Orbital Gateway .NET(2.0)SDK [ ^ ]

它指出:
.NET SDK由两个组件组成:
•ptDotNetSDK.dll –包含事务和响应类的主dll.
•PTDotNetService.exe –包含核心引擎的服务，在单独的进程中作为Windows服务.当SDK在服务"模式下运行时，将使用此服务.

因此，它应该是您将要使用的SDK的一部分.此外，文档状态还需要确保DLL位于特定文件夹中.如果您在阅读完文档后仍然遇到问题，那么我建议您就此问题与他们联系.

Have a look at this:
Chase PaymentTech: Orbital Gateway .NET (2.0) SDK[^]

It states:
The .NET SDK is made up of two components:
• ptDotNetSDK.dll – The primary dll containing the Transaction and Response classes.
• PTDotNetService.exe – A service containing the core engine within a separate process as a Windows Service. This service is used when the SDK is operated in Service mode.

Thus, it should be the part of the SDK that you are about to use. Further, document states you need to make sure that the DLL is present in a specific folder. If you still face issue after going through the document then I would suggest you to contact them regarding the same.