Testing And Troubleshooting; Testing; Troubleshooting - GarettCom 5843HRT User Manual

4.

TESTING AND TROUBLESHOOTING

4.1

TESTING

Models 5843HRT and 5844HRT lend themselves to easy installation and testing. Testing the units
requires transmitting and receiving data or setting the Test Mode switch to ON while observing that
the diagnostic LEDs are illuminating in the proper sequence.
To test whether a unit is transmitting and receiving correctly, insert a short fiber jumper between its
T and R optical ports, transmit a signal (or turn the Test Mode Switch ON) and note that all four
diagnostic LEDs should illuminate during communication (refer to Figure 5).
To test the units in a loop configuration, two Link/Repeaters are required. Connect short Fiber
jumper from the T optical port of one Link/Repeater to the R optical port of the other. Set the
Repeat Switch for one of the units to ON and the other to OFF. The unit with the Repeat Switch in
the OFF position is the Master. Using the Master, transmit and receive (or use the Test Mode
Switch in the ON position) through the other unit in the repeat mode. Observe that the diagnostic
LEDs illuminate during communication (refer to Figure 5).
When a Link/Repeater is not connected to an IED and is in the "repeat" mode, Transmit (pin 2 or pin
3) depending on the position of the DCE/DTE switch) and Chassis Ground (pin 1) should be
connected to Signal Common (pin 5). This will prevent any spurious noise from being induced into
the fiber optic loop circuit while servicing an IED.
Models 5843SHRT and 5844SHRT (only)
When not connected to an IED and in the repeat mode, the Link/Repeater should have Chassis
Ground (pin 1) connected to Signal Common (pin 5). If these pins are not tied together, noise could
be induced into the fiber loop. This is also necessary when servicing an IED in order to keep the
fiber loop and the Link/Repeater operational.
The jumper connecting Chassis Ground and Signal Common should be
disconnected before reconnecting Models 5843SHRT or 5844SHRT to
an IED.
4.2

TROUBLESHOOTING

If the unit does not work properly, use the following check list:
• Is the unit properly powered?
1) Verify the unit is receiving the correct power.
2) Is the Power LED on.
2) If required, make sure power from D-connector is on Pin 9.
• Check that the diagnostic LEDs are responding to the optical and electrical activity.
• Is the unit mated properly to the IED? If an adapter is used, check that pin assignments are
connected correctly.
1) Are the fiber cables connected properly? T to R; not R to R nor T to T.
2) Is the DTE/DCE switch and the Repeat switch set to the proper positions for the
application?
WARNING
4-1
Models 5843, 5844, 5843S and 5844S
RS-232 or TTL