Peter Maggs and Vaughan Wesson, February 2003.

Introduction

Guria V5.11A introduced software support for the Kelunji Ethernet hardware. This introduction highlighted a couple of minor modifications required to the Kelunji hardware. Overall, to connect a Kelunji to an Ethernet port, the following four things must be checked.

1. An appropriate cable is required from the Kelunji Ethernet port to an RJ-45 connector
2. Modification of the DK1 PCB. This is changing a 39pF capacitor for a 39nF capacitor
3. Modification of the DC2 PCB and check that the correct Ethernet transformers are installed
4. Check that you have Guria K5.11A or later installed

Ethernet Cable

It is expected that users will usually want to use the twisted pair Ethernet cabling rather than the older coaxial cabling. Cables may be made in two configurations, these are referred to as "normal" and "crossover". A normal cable is used to connect a Kelunji to a socket in an office or an Ethernet hub. However, if wishing to connect directly from a Kelunji to a PC then a crossover cable is required.

Normal Cable

Crossover Cable

DK1 Modification

Remove the DK1 circuit board from the chassis. The modification required is to swap a 39pF capacitor for a 39nF capacitor for the Ethernet transceivers (MC68160) phase lock loop circuit. The location is shown in the diagram.

DC2 Modification

To work on the DC2 circuit board, all other PCBs (DDx, DK1/DI1 and DPx) must be removed from the black metal chassis. Then remove the black metal chassis by undoing the four mounting bolts and disengaging it from the plastic locating stand-offs. Disconnect the ground cable connecting the DC2 to the case. Undo the jam nuts holding each connector to the case. Remove the DC2 circuit board from the case, taking care not to lose the rubber seal rings.

This diagram shows the location of the following modification.

1. On the connector side of the PCB there is a trace connecting U18 pin 2 and U18 pin 7 to a via which is connected to GND. Cut this trace in two places to disconnect U18 pin 2 from U18 pin 7 and from GND.
2. Connect a 100nF capacitor from U18 pin 2 to the via (GND). Also connect a 100nF capacitor from U18 pin 7 to the via (GND).
3. Check that U18 has a FL1066 or PE68812 part number installed. Some boards have been found to have U18 and U17 swapped. (U18 should be much larger than U17)
4. Reassemble the DC2 and case taking care with the rubber sealing rings, and tightening the connector jam nuts evenly. Reinstall the black metal chassis and all circuit boards.

System Check

After performing these modifications and installing the latest Guria software, the following steps can be performed to check the basic functionality of the Ethernet interface.

• Find an Ethernet hub in your office that you can use that has an LED for each port. Power up the hub
• Connect the Ethernet cable to the Kelunji and the Ethernet hub
• Power up the Kelunji and go in to the "Settings:Serial:Network interfaces" menu
• Leave the FTP and Web server disabled
• Set Interface enabled to Yes, Open mode to 0, and Port number to 0
• At the bottom of the menu, press <Return> to save values
• The second line of the display should then be a Network Interface status line. It should be displaying "I/f #1, pt=Enet closed"
• After 10 or 20 seconds this should change to "I/f #1, pt=Enet enabled". At this time, the LED on the Ethernet hub should come on indicating a valid link

For more detailed testing, see TN200302B that discusses Internet based telemetry.