Most Common Problems; Most Common Video Problems; Most Common Data Problems; Most Common Optical Problems - Moog Focal 903 User Manual

903-0628-00 Rev. 1
7.2

Most Common Problems

7.2.1 Most Common Video Problems

 Improper impedance matching (75 ohms) or missing ground connection.
 Video signal "too hot", i.e. >> 1 Vpp nominal. (Camera outputs may be set to drive long copper
cables.)
 RG-179 OK but attenuates at higher frequencies, so limit to a few meters or use RG-59 for long runs.
 Isolation required, e.g. Deerfield Labs transformer P/N: 262-1, BNC-BNC (grounding problems
between camera, mux, monitor).
 Wrong switch configuration settings on video card for composite versus S-video (Y/C) and RGB (see
video card section of this user's guide, Table 4-3).
 Anti-piracy protection on VCR tapes or DVDs during testing (e.g. Macrovision)

7.2.2 Most Common Data Problems

 Improper RS-485 auto sense settings (see RS-485 section of this user's guide, Table 4-7)
 AIB plug-ins not installed in proper orientation or socket, or different card types used in remote and
console end.
 Incorrect RS-485 polarity: AIB-485 card's standard is negative pin is inverting and RS-485 biased with
619 ohm pull up/down resistors plus optional 120 ohm terminator. When the two-wire polarity is
correct, the red receive LED is typically on less often then when the wires are reversed.
 No or poor terminations: terminators and impedance controlled cable is needed at high data rates
(> 500 kbps).
 Poor cabling or grounding: Use twisted pairs for differential serial links. Verify proper grounding and
shielding.
 AIB switch settings: Incorrect or default settings need to be changed.
 RS-422 Cross-over: Pins 1, 2 (Mux Rx) and 3, 4 (Mux Tx) are the same at both ends. Hence RS-422
coming into the mux on pins 1/2 at one end will exit the mux at the other end on pins 3/4 for the
corresponding channel.
 MS900 AIB settings: Jumper on AIB must be set one way for the remote and the opposite way for the
console.
 ARCNET AIB settings: Mux and sonar settings must match, per manual.

7.2.3 Most Common Optical Problems

 Bad or contaminated connections (excessive loss and/or back reflection) cause 80% of all link
problems.
 Excessive fiber bends or damaged cables cause excessive optical loss, particularly at 1550 nm.
 Insufficient fiber bandwidth, particularly in multi-mode fiber, can cause intermittent problems on long
cables.
 Optical overload (not enough attenuation) during bench tests can cause link faults or errors.
 Dust contamination from bushings or connectors not being covered (especially turrets) can cause link
faults.
 Mixed multimode/singlemode fiber jumpers (orange/gray vs yellow jackets) cause optical faults.
 Refer to section 5.3 of this document for Fiber Handling Guidelines.
Focal Technologies Corp.
Model 903-HD User's Guide – FMB-X-2.5
Page 7-2