Troubleshooting common problems

Interface exits on startup

If the interface immediately exits upon startup, the most likely cause is that required command line parameters are not specified. TCPResponse requires the following command line parameters:

• -ps= (point source character or string)

• -id= (interface identification number)

• -host= (PI Server name and port number)

If the user omits any of these parameters, the interface exits. For many scenarios this information will be written to the message logs.

No new value for a point

If a point does not receive new value (that is, the value remains at Pt Created), a likely cause is that the interface node does not have sufficient privileges to send data to the PI Server. A symptom of this problem is a -10401 error in the message log file. The solution is to check the entries in the PI Proxy Table (Data Archive v3.2) or the PI Trust Table (PI Server v3.3 and higher).

Another reason that a point is not getting a new value is that the interface has not loaded the point. To confirm whether the interface has loaded a point, set the point's Location5 attribute to 1. Within two minutes, TCPResponse writes to the log file information regarding whether it has loaded the point. For example:

• PI TCPResponse 1> pt (tcpresptest) debug setting is 1

• PI TCPResponse 1> pt (tcpresptest) LOADED

or

• PI TCPResponse 1> pt (tcpresptest2) debug setting is 1

• PI TCPResponse 1> pt (tcpresptest2) REFUSED; -id/Location1 mismatch; -id=1, Location1=9

If not one of the above, the reason is most likely the communication with the data source. The configuration of the PI point may not be accurate or there could be network issues between the interface node and the data source, for example. Some of this information might be written to the message logs, especially if debugging is enabled using Location5.

Value of 0 for a point

A value of 0 for a point means that the measured response time is less than 1 millisecond.

Value of Bad Input for a point

A value of Bad Input for a point means that the interface encountered an error during the measurement of response times. A common error is the inability to translate the device specification into an IP address. For example, the user want to measure the response time of the Web server named www.somecompany.com. Accordingly, the user configures a point such that its InstrumentTag contains device=www.somecompany.com;

Before the interface can send an HTTP request to device=www.somecompany.com;, it first has to find the IP address of this machine. If this IP address lookup fails, TCPResponse writes Bad Input to the point.

See Principles of operation for PI Interface for TCP Response for more reasons that the interface writes Bad Input to a point. In addition, you can set the point's InstrumentTag to 3 to tell the interface to print out the reason it is writing Bad Input.

Value of I/O Timeout for a point

A value of I/O Timeout for a point indicates that the interface did not receive a response message within the timeout time from the target data source. The timeout time for a point is one of the following:

• the Location3 value, if Location3 is non zero

• the value of the –wt command line parameter if Location3 is zero

• 5000 milliseconds if Location3 is zero and the –wt parameter is not specified