When ERP-Scale attempts to connect to the SAP Gateway, the connection fails with error
ERROR max no of 200 conversations exceeded
The solution is discussed in the following SAP Note: SAP Note 314530
If an RFCserver program registers with 100 threads on the R/3 gateway, for example, 100 connections are kept in the server program. Each RFC that runs on such a connection results in an additional entry in the connection list of the RFC server program. This means that a maximum of 200 connections is possible under full load. Adjust the value of the environment variable accordingly.