GSP-830 User Manual 128 3. Press F2 (Self Test). Self Test...F 2 4. The GPIB result appears at F1. If the result is Fail (underlined), contact service personnel. GPIBPass FailF 1 GPIB constraints Keep these rules when using the GPIB interface. • Altogether less than 15 devices & 20m cable length, 2m between each device on the bus • Unique address assigned to each device • At least 2/3 of the GPIB devices turned on • No loop or parallel structure allowed View System Information View system error Panel operation View the bottom of the screen, the error message area. If there is a system error, the message appears in red. Center : 1.5GHz(EXT Unlock)EXTUnlock AmpUncal • Inappropriate RBW or VBW is selected. • Frequency is less than 15MHz and amplitude is less than −30dBm. EXTUnlock External reference input is not working properly. LO1Unlock Local oscillator 1 is not working properly. LO3Unlock Local oscillator 3 is not working properly. MedUnlock ±1ppm stability signal is not working properly. Appears only when the optional ±1ppm Stability Module is installed. RefUnlock Internal reference signal is not working properly.