What about 

w $system.TCPDevice.LocalAddr()?

HealthConnect is going to have your Health protocols, for example Hl7v2 that will not be in regular IRIS.

Since you've had successful "runs", I wonder if it's a memory issue.  You could increase your partition size or

Set $zstorage=$zstorage*10  // temporarily increase partition size

And see if that helps (ie changes the number of lines processed)