Optimod-AM 9400 V1.2 Operating Manual - Orban
Optimod-AM 9400 V1.2 Operating Manual - Orban
Optimod-AM 9400 V1.2 Operating Manual - Orban
- No tags were found...
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
OPTIMOD-<strong>AM</strong> DIGITAL TROUBLESHOOTING 5-13<br />
C) Click the “Networking” tab.<br />
D) Set “Type of dial-up server I am calling” to “PPP: Windows 95 / 98 / NT4 / 2000,<br />
Internet”<br />
E) Select the “Settings” button. Make sure all PPP settings are unchecked, and<br />
then click “OK.”<br />
F) In “This connection uses the following items,” uncheck all except for “Internet<br />
Protocol (TCP/IP).” You can also leave “QoS Packet Scheduler” checked if you<br />
like.<br />
G) In “This connection uses the following items,” select “Internet Protocol<br />
(TCP/IP)” and then click the “Properties” button.<br />
The “Internet Protocol (TCP/IP) Properties” window opens.<br />
H) Choose “Obtain an IP address automatically” and “Obtain DNS server address<br />
automatically.”<br />
I) Click the “Advanced…” button on the “Internet Protocol (TCP/IP)” Window.<br />
J) In the “Advanced TCP/IP Settings,” select the “General” Tab; make sure that<br />
no check boxes are checked.<br />
K) Click “OK” to dismiss the “Advanced TCP/IP Settings” window.<br />
L) Click “OK” to dismiss the window whose name is your new connection.<br />
M) Restart your computer. (This resets the serial port and reduces the likelihood<br />
that you will encounter problems connecting to the <strong>9400</strong>.)<br />
Troubleshooting IC Opamps<br />
IC opamps are operated such that the characteristics of their associated circuits are<br />
essentially independent of IC characteristics and dependent only on external feedback<br />
components. The feedback forces the voltage at the (–) input terminal to be<br />
extremely close to the voltage at the (+) input terminal. Therefore, if you measure<br />
more than a few millivolts difference between these two terminals, the IC is probably<br />
bad.<br />
Exceptions are opamps used without feedback (as comparators) and opamps with<br />
outputs that have been saturated due to excessive input voltage because of a defect<br />
in an earlier stage. However, if an opamp's (+) input is more positive than its (–) input,<br />
yet the output of the IC is sitting at –14 volts, the IC is almost certainly bad.<br />
The same holds true if the above polarities are reversed. Because the characteristics<br />
of the <strong>9400</strong>'s circuitry are essentially independent of IC opamp characteristics, an<br />
opamp can usually be replaced without recalibration.<br />
A defective opamp may appear to work, yet have extreme temperature sensitivity. If<br />
parameters appear to drift excessively, freeze-spray may aid in diagnosing the problem.<br />
Freeze-spray is also invaluable in tracking down intermittent problems. But use<br />
it sparingly, because it can cause resistive short circuits due to moisture condensation<br />
on cold surfaces.