 adding parameter to the getInstrumentList Web service operation that will specify the type of instruments to be searched. For example, passing the string "GPIB" as a filter parameter to the getInstru- mentList Web operation, will limit the search only to GPIB instruments. Error messages returned by the Web service in case of failure should resemble the error codes provided by the NI-VISA implementation. 12.3.2.2 Case Study: Remote Experiment: "Bartlett Study of a Bridged-T 2-Port" They were implemented two approaches of this remote experiment, in order to test the efficiency of the BPEL-based version compared to the "resource-intensive" LabVIEW approach (its panel, with the UUT layout, can be seen in Figure 12.50) Tele-Measurement Services for m-Learning podit var2.vi Project Operate Tools Window Bridged T 2-port (Bartlett Study) TP (4) TP(6) TP (5) TP (7) U1-1V HM8142 HP34401A DMM Displayed Value Take Measurement Stop application Figure 12.50 VI panel of the "Bartlett study of a Bridget-T 2-port." The possible remote experiments are of two types: Resistance measurement (when SW3 = OFF <=> voltage source NOT in the circuit); one can measure the resistance with short-circuited semi-section (SW1 = ON, SWO = ON), and with open-circuit semi-section (SW1 = SWO = OFF). Voltage measurement (SW3 = ON, voltage source in the circuit it), at the input, at the output and in the intermediary nodes. BPEL version of the remote experiment on "Bartlett study of a Bridget-T 2-port" As shown before, the possible remote experiments offered by this scenario are of two types: Resistance measurement (when SW3 = OFF voltage source NOT in the circuit); one can measure the resistance with short-circuited semi-section (SW1 = ON, SWO = ON), and with open-circuit semi-section (SW1 = SWO = OFF). Voltage measurement (SW3 = ON, voltage source in the circuit it), at the input, at the output and in intermediary nodes. Service Delivery Platforms Receive input Switch configuration Multimeter configuration Source configuration Measurement read Figu