TX: TRANSMIT ACTIVITY (ALL CARDS) - This LED illuminates when the card is sending a packet. This indicates normal operation.

COL: COLLISION PRESENCE (ALL CARDS) -- This LED illuminates when a card is receiving a packet at the same time it is transmitting a packet. Occasional collisions are normal in an Ethernet network. This does not denote an error condition.

RX: RECEIVE ACTIVITY (ALL CARDS) -- This LED illuminates when the card is receiving a packet. This indicates normal operation.

LL: LINK FAULT (8340B and 8342B) - This LED illuminates when the fiber cable is broken, provided break detection is on.

JAB: JABBER (8340B and 8342B) -- This LED illuminates when a transceiver interlock circuit is activated. This circuit prevents a runaway AUI controller from saturating the network.

HL: HIGH LIGHT (8340B and 8342B) -- This LED illuminates if the received power is greater than the receiver saturation level.

FL: FIBER LINK (8341B, 8345 and 8346) - This LED illuminates when the RX fiber port is receiving Link Pulses. The LED will not illuminate when the fiber cable is broken or the other adapter card or concentrator is not transmitting Link Pulses.

POL: TWISTED PAIR POLARITY (8345) -- This LED illuminates when the polarity of the twisted pair receive wires is not correct. The CN8345 adapter will automatically detect and alter it's receive circuitry to correct this condition. The user is alerted to the condition by the illumination of the LED.

TPL: TWISTED PAIR LINK (8345) -- This LED illuminates when the Twisted Pair receive port is receiving Link Pulses. The LED will not illuminate when the twisted pair cable is broken or the other adapter card or concentrator is not transmitting Link Pulses.

4.2.1 Fiber Broken / Jabber Indicators
Use the following table if your card is a CodeNet 8340B or 8342B:

Condition Code	Jabber Auto Reset Switch	Link Fault Red	Jabber LED	Error Condition
1 2 3 4	On On Off Off	Steady Off Steady Off	Flashing Flashing Off Steady	Fiber Broker Jabbering Fiber Broker Jabbering
COND.		CORRECTION
1 or 3		Check connection between cable and card. See following steps.
2 or 4		Indicates transmission taking too long. Doesn't harm network, just slows it down. Use checkout steps below.

In Conditions (1) and (2), because the Jabber Auto-Reset switch is ON, the card will reset itself and continue operating normally with- out powering down. In Conditions (3) and (4), you must power down the computer, correct the problem and power up again to reset it.

If the link fault LED is on, check to make sure that cables are con- nected properly and, if using SMA-906 connectors, that the half- length alignment sleeves are on the tips of the connectors going into the 8340B or 8342B, and that full length alignment sleeves are present in the passive star ports. If the link fault LED remains on, test the optical power in the receive fiber.

To test, you must first disconnect all other cables from the star or shut down all DTEs connected to the star. Put switch 5 in the down (test) position. If the average power at the receive fiber is less than -40 dBm for an 8340B, or less than -33 dBm for an 8342B, the problem is probably in the fiber or the passive star. Check the loss in the passive star using a short jumper cable. If fiber loss in the passive star using a short jumper cable. If fiber loss is determined to be excessive, try cleaning the connector ends with a soft cloth or lens tissue dampened in isopropyl alcohol.

If fiber and passive star light levels are deemed acceptable, test the output power of the 8340B or 8342B and compare to specifications. Note: The power meter will read average power which is 3 dB less than the peak power specifications.

Caution: You must return switch 5 to the up position before reconnecting to the network.

If a power meter is not available, a simple pen light is an excellent optical source for checking fiber continuity. Shine the light in one end of the cable. If you see light on the other end, the fiber is not broken. If you see no light, the fiber is broken. Replace the cable.

On the 8340B and 8342B the "High Light" indicator (HL), if ON, indicates that the receiver is being saturated (receiving too much optical power). While this is not injurious to your network, it will most likely slow it down. This condition should be corrected by attenuating the incoming signal.

The front panel lights on the 8341B, 8345 and 8346 indicate the following conditions. If any of these indicators illuminate, follow the error correction steps given below or in Section 4.4, which are applicable to all three units.

FIBER LINK (FL) NOT ILLUMINATED

If the Fiber Link LED is not on after cables have been connected and the other adapter card or concentrator has been powered up, check to make sure that cables are connected properly and, if using SMA- 906 connectors, that the half-length alignment sleeves are on the tips of the connectors going into the 8341B, 8345 or 8346 (see Figure 2-3). If the fiber link LED remains off, disconnect the RX fiber from the adapter card and connect it to an optical power meter (CodeNet CTC-2000 or equivalent). If the average optical power is less than -30 dBm, there is excessive loss in the fiber or the companion unit's transmitter is not supplying sufficient power. Try cleaning the fiber ends with a soft cloth or lint-free paper dampened in alcohol and test the transmitter output of the companion unit.

If a power meter is not available, a simple pen light is an excellent optical source for checking fiber continuity. Shine the light in one end of the cable. If you see the light on the other end, the fiber is not broken. If you see no light, the fiber is broken. Replace the cable.

If any of the CodeNet cards do not operate properly, follow the steps listed here to verify correct installation,

(1) Verify that the network connectors are securely attached (TX to RX, RX to TX).

(2) Check the cable connections to other computers and devices.

(3) Ensure that the interconnecting cables used meet Codenoll standards.

(4) Ensure that you have correctly configured your system for the CodeNet cards being used, employing the program on the Installation diskette. If a ROM device is installed, make certain it was enabled during the Autoset configuration program.

(5) Ensure that you have copied any required software drivers from the Installation diskette as instructed in documentation included in your network software package.

(6) If more than one 8340B, 8341B, 8342B, 8345 or 8346 card is installed, ensure that you have selected a different IRQ channel for each.

(7) Verify that the network software is loaded correctly.

(8) If a ROM device is installed on the adapter card, verify that the correct ROM size is selected. Verify that the ROM device is correct for the type of computer system and network software being used. Ensure that every pin on the ROM device is firmly seated in the socket.

(9) Ensure that the CodeNet card is completely seated in the computer's expansion slot.

(10) Verify all appropriate alignment sleeves (if any) are present.

(11) Ensure connector and faces are free of dirt and debris. Clean with soft cloth or lint free paper dampened with isopropyl alcohol.