Crystal Vision
Trouble shooting
27/10/2006
14
GPI 36 User Manual R3.0
Basic fault finding guide
The Power OK LED is not illuminated
Check that the frame PSU is functioning – refer to the appropriate frame manual for detailed
information
Check that the card is seated correctly in the frame
The card no longer responds to Statesman/front panel control
Check that the card is seated correctly and that the Power OK LED is lit
Check that the card-edge Rx and Tx LEDS flash (Comms LED in an Indigo frame) when Statesman
communication control is attempted
Check any active control panel/Statesman cabling
Check if the control panel/Statesman can control another card in the same rack
If necessary re-set the card
One or more GPI input lines do not change state
Use the input testing function for semiconductor driver inputs
Check the affected cabling and external devices
How does the input test work?
The input function can be set to detect the presence of an open-collector (or open-drain) output even
when the output is inactive (not pulling down to ground). If IP Conn is selected, the input is
periodically connected to a negative voltage and sensed whether it pulls below -1V (assumed to be an
open circuit) or whether it clips at -0.7V (assumed to be an open collector/open drain parasitic diode).
The test current is limited to less than 50mA. When the connectivity test is enabled it will be
performed at least two times every second.
Re-setting the card
If required, the card may be reset by simply removing the rack power and re-applying power after a
few seconds or by removing the card from the rack and then re-inserting the card
It is safe to re-insert the card whilst the rack is powered
The output error LED lights when there is no output error
The Statesman output error LED in GPI output mode will be in an undefined state at currents above
5mA when the output state is set low. This may cause the LED to illuminate inappropriately.
This is because the voltage at the sense terminal approaches the maximum TTL input low voltage
(0.8V) when sinking more than 5mA through a GPI output set low. There is no problem when a GPI
output is set high.
